About 600 miles off the coast of South-Eastern Africa lies the fourth largest island in the world, Madagascar. Famed for its lush green tropical forest, misty highlands, temperate climate and 3,000 miles of coastline, this jewel in the Indian Ocean is home to one of the most exotic creatures in the world – the lemurs.
Madagascar's 160 million years of isolation as a landmass has shaped an ecosystem and habitat that's perfectly suited and unique to the existence of lemurs. The lemurs themselves have been on the island for over 40 million years, giving them distinctive features quite different from any other animal in the world. In appearance, lemurs are a mixture of many animals – squirrel, cat, dog, and monkey. Some have faces that closely resemble raccoons or skunks and have many characteristics of apes. But when there are 101 species of an animal, looks and behavioral patterns vary widely.
Lemurs are basically nocturnal creatures and move about at night. "Lemures" in Latin means "Spirits of the night". Lemurs are herbivorous animals and their main diet is plants. 55 percent of the island's plant life constitute food for lemurs. Black lemurs, for example, eat leaves, flowers and fruit. So do the inri, another species of lemur. Insects also form an important part of the diet, especially for the smaller species of lemur. Greater bamboo lemurs live off the inner pith of giant bamboo found in forest pockets of the eastern highlands.
Among the existing species, the diademed sifaka and the indri lemurs are the largest and can weigh up to 15 lbs at the most. The smallest, the pygmy mouse lemur, weighs only 1 oz, making it the tiniest primate in the world.
Man first landed in Madagascar as recently as 2,000 years ago. The fate of lemurs has been threatened ever since. Archaeoindris fontoynontii, the giant lemur weighing as much as 440 lbs, was among the first species to become extinct. Once found virtually all over Madagascar, lemurs are now ensconed into just 20 percent of their original habitat, most of it in the central and east coast highlands. According to a recently released report of the IUCN (International Union for Conservation of Nature) Red List of Threatened Species, of the 101 species of lemurs, 22 are on the brink of extinction, 48 are endangered, and 20 are vulnerable.
The threats to the lemur's survival is similar to many endangered animals of the world - a burgeoning human population's hunger for more land which translates into more clearing of forests for agricultural purposes. Poverty-stricken Malagasys have resorted to burning down the nation's scarce forests to grow crops. Hunger has also led to the hunting of lemurs for meat, an unusual occurrence until a few decades ago.
Political turmoil also has taken a toll on the laws and mechanisms that safeguard and conserve forest resources. Armed gangs, working in cahoots with the timber mafia, have taken advantage of the political vacuum to pillage protected forests for ebony and rosewood. Over $100 million dollars of wood stolen in this manner have made their way to China for use in furniture. The immediate fallout is on the habitat of the lemur.
Despite laws protecting the lemurs, the creatures are not just hunted as a delicacy, but for superstitious reasons too. The aye-aye lemur, a 5.1 lbs animal, is considered a harbinger of death by some natives and is quickly exterminated if spotted in the vicinity of their villages.
The ring-tailed lemur is among the most well-known and loved lemur species. It is at the top of the list of the illicit pet trade industry. Found mostly in the southern fringes of Madagascar, this beautiful animal, with an off-white coat and a long zebra-striped tail, is sold to hoteliers and tourists for a ridiculously low sum of $2. Being a popular animal, it is also inhumanely kept in zoos all around the world for human entertainment and profit.
The black lemur is another highly endangered species. There are about 10,000 of them in the North-western parts of Madagascar and in some of the islands off the North coast. The black lemur stands about 38 inches tall and weighs about 5 lbs. The black lemur faces common threats like other lemur species. Man's proximity has brought this species into confrontational situations where they have been killed for raiding crops.
Superstitions sometimes can work in favor of the lemurs. For example, the inri is believed to be carrying souls of ancestors. Villagers refrain from killing them.
But lemurs desperately need protection. Loss of habitat can have serious consequences for the breeding or reproduction of lemurs. The lemurs have very short mating and birth windows that are synchronized to seasons when food availability is at its peak. The female vagina opens up for a very brief period of the day, leaving a small window for reproductive activities. High levels of energy exhaustion during such periods account for high mortality among adult lemur females.
Despite protests from local villages, the Ranomafana National Reserve Park was created by the forest authorities of Madagascar. The Ranomafana reserve is a 15 km strip of virgin forests not far from the east coast setup primarily to protect the lemurs inhabiting it. Similarly, nearly 20 national parks have sprung up in the last few decades – especially along the entire eastern and southern coastal belts – to protect endangered species in those sensitive places where they may come into direct contact with human habitation.
The blue-eyed black lemur, an inhabitant of the sub-tropical moist and dry forests in the north-western tip of Madagascar, is a beneficiary of serious conservation measures. Thanks to the endeavors of organizations that have put into place natural resource management and ecological research programs to monitor and mitigate the loss of valuable forest resources in that region, the rare blue-eyed species of lemur is on a comeback trail and finds itself out of the IUCN’s list of the 25 most endangered primates on the planet.
But serious challenges remain. In addition to rapid habitat loss, climate changes may pose the biggest threat to the survival of lemurs. A study found that 60 percent of the 57 species examined may find their habitat reduced by an alarming two-thirds in the next seventy years solely due to climate change.
Coal is our most abundant “fossil fuel”. China is now the chief coal producer, followed by the United States. Other major coal producers are Australia and India. Five countries – China, the United States, India, Japan and Russia – account for more than 75% of worldwide coal consumption.
The US has more coal than the rest of the world has oil. There is still enough coal underground in the United States alone to provide energy for the next 200 to 300 years. But coal is far from a perfect fuel. Trapped inside coal are traces of impurities like sulfur and nitrogen. When coal burns, these impurities are released into the air.
While floating in the air, these substances can combine with water vapor (for example, in clouds) and form droplets that fall to earth as weak forms of sulfuric and nitric acid – scientists call it “acid rain.” There are also tiny specks of minerals, including common dirt, mixed in coal. These tiny particles don't burn and make up the ash left behind in a coal combustor. Some of the tiny particles also get caught up in the swirling combustion gases and, along with water vapor, form the smoke that comes out of a coal plant's smokestack.
Also, coal, like all fossil fuels, is formed out of carbon. All living things, even people, are made up of carbon. But when coal burns, its carbon combines with oxygen in the air and forms carbon dioxide. Carbon dioxide is a colorless, odorless gas, but in the atmosphere, it is one of several gases that can trap the Earth's heat. Many scientists believe this is causing the Earth's temperature to rise, and this warming could be altering the Earth's climate.
Threats To Wildlife From Coal Mining
Surface mining of coal is the method resorted to by the industry when coal deposits are found just below the Earth's surface. This happens to be the most used mining methodology of coal world over and has a direct and negative effect on ecosystems, environment and wildlife of places where such activity is carried out.
Excavation of the soil and heaping of spoils damages the Earth's surface beyond repair and causes decimation and displacement of wildlife species. It's worse for sedentary species like reptiles, small mammals, beavers and burrowing rodents, all of whose primary habitat is the Earth's surface.
Pollution of aquatic habitats is another outcome of surface mining for coal. Wastes and chemicals from it trickle and seep into streams, rivers and underground water-bodies. As a result, effects are manifested in places that are far away from mining sites. Most damaging are the kinds of chemicals pumped into the ground through pipes – mercury, methyl-mercury, cyanide and arsenic.
Mercury contamination is one of the most detrimental outcomes of coal mining. In the North-east mountain ranges of the US, it's been known to contaminate fresh-water lakes and in turn affect fish and fish-eating birds while damaging their neurological and reproductive systems. Studies show that 92 species from 11 North-Eastern states from Maine to Virginia are vulnerable to mercury contamination.
The wetlands that support a vast array of bird-life are especially open to one of the worst forms of pollution – methyl-mercury poisoning. Air pollution arising out of coal mining can quickly acidify water bodies. It hastens the process by which bacteria convert inorganic mercury from coal into organic methyl-mercury. Bogs, coastal marshes, beaver ponds, foggy mountaintops and forest floors are all absorbers of methyl-mercury. From such wetlands, it permeates into terrestrial grounds and this can corrupt an entire food web. Biomagnification takes over, and with each step of the food chain concentrations of mercury rise. This happens when creatures in these wet habitats feed on plant debris containing mercury, allowing it to enter terrestrial food sources. Rusty blackbirds and Saltmarsh sparrows have shown the highest levels of mercury contamination. Mercury poisoning of Virginia water-bodies threaten to hamper the Saltmarsh sparrow's ability to choose safe nesting sites.
Small traces of methyl-mercury, that were previously ignored as being harmful, have now revealed the adverse effects it can have on reproduction of species. Just a minuscule amount of 1.2 parts per million of methyl-mercury found in the blood of the Carolina wren have accounted for a 20 percent drop in their reproductive capacities. The wrens are scavengers and glean the forest floors for spiders, which too are contaminated.
Most surprising is the case of the tiny Dome Island in the middle of the pristine Lake George in the uplands of New York State. This untouched 16-acre island in the Adirondack region is considered to be a conservation gem and is home to species of songbirds like the red-eyed vireos, black-capped chickadees and song sparrows that flutter among ancient cedars, beech, hickory and oak. Shockingly, these birds have revealed the highest concentrations of mercury in the North-east region. They are victims of airborne mercury pollution. Almost 50 tons of neurotoxins are belched into the atmosphere annually by coal-based power plants in the US. This “atmospheric deposition” of mercury is a global hazard, but is more pronounced in the bio-diversity rich hotspots that lie downwind to coal-burning epicenters of Ohio, Illinois, Pennsylvania and Indiana.
Wanton mining practices elsewhere in the world have results in coal fires that can burn for decades, as in the case of numerous mines in Eastern India. It releases fly ash into the atmosphere, along with smoke full of toxic chemicals and greenhouse gasses. Coal mine methane, a greenhouse gas emitted by mining of the mineral, is 20 times more toxic than carbon dioxide.
In China, even though 95 percent of the mines are underground, the threat of a methane outburst always looms.
Other problems that have environmental consequences are coal storage piles or waste piles. These afflict countries like China, Russia, the US, Indonesia, Australia and South Africa in a considerable way.
The biggest threat to the environment comes from countries with huge reserves of coal. A fear for these countries is there could be alternative sources of energy in the future that could replace a fossil-fuel like coal. So the idea of mining and finishing whatever stocks of coal remain before such a replacement happens weighs heavily on the minds of policy makers. Hence the near-frenetic activity in coal mining in places like India and China. Also, both depend heavily on this mineral to make-up for the huge shortfall in oil to meet their ever-growing energy needs.
Coal Impact On Climate
Coal is an abundant fuel source that is relatively inexpensive to produce and convert to useful energy. However, producing and using coal impacts the environment.
Climate change is one of the greatest environmental challenges we face. Climate impacts affect the entire planet. Unchecked carbon pollution leads to long-lasting changes in our climate, such as rising global temperatures; rising sea level; changes in weather and precipitation patterns; and changes in ecosystems, habitats and species diversity. These changes threaten human and wildlife health and welfare.
Environmental risks include more heat waves and drought; worsening smog (also called ground-level ozone pollution); increasing the intensity of extreme events, like hurricanes, extreme precipitation and flooding; and increasing the range of ticks and mosquitoes, which can spread disease such as Lyme disease and West Nile virus.
Overwhelmingly, the best scientists in the world are telling us that our activities are causing climate change – based on troves of data and millions of measurements collected over the course of decades on land, in air and water, at sea and from space.
Emissions From Burning Coal
Most of the coal consumed is used as a fuel to generate electricity. Burning coal produces emissions that adversely affect the environment and human health.
There are several principal emissions resulting from coal combustion:
Sulfur dioxide (SO2), which contributes to acid rain and respiratory illnesses
Nitrogen oxides (NOx), which contribute to smog and respiratory illnesses
Particulates, which contribute to smog, haze, and respiratory illnesses and lung disease
Carbon dioxide (CO2), which is the primary greenhouse gas emission produced from the burning of fossil fuels (coal, oil, and natural gas)
Mercury and other heavy metals, which have been linked to both neurological and developmental damage in humans and other animals
Fly ash and bottom ash, which are residues created when coal is burned at power plants. Fly ash is generally stored near power plants or placed in landfills. Pollution leaching from ash storage and landfills into groundwater and the rupture of several large impoundments of ash are environmental concerns.
Coal And Water
Coal not only pollutes our skies and fuels climate change, it also deprives us of our most precious resources: water. The world’s rapidly dwindling freshwater resources could be further depleted if plans for hundreds of new coal power plants worldwide go ahead, threatening severe drought and competition.
If all the current proposed coal plants are allowed to be built, the water consumed by coal power plants around the world would almost double. Globally, coal power plant units already consume enough water to meet the basic water needs of 1 billion people. A quarter of the proposed new coal plants are planned in regions already running a freshwater deficit, where water is used faster than it is naturally replenishing.
Coal is one of the most water-intensive methods of generating electricity. According to the International Energy Agency, coal will account for 50% of the growth in global water consumption for power generation over the next 20 years. Research shows that if the proposed coal plants come online, their consumption of water will increase by 90%.
Public Lands Mismanaged
America has more coal than any other fossil fuel resource. The United States also has more coal reserves than any other single country in the world. In fact, just over 1/4 of all the known coal in the world is in the US. The United States has more coal that can be mined than the rest of the world has oil that can be pumped from the ground. Currently, coal is mined in 26 of the 50 states.
The Bureau Of Land Management (BLM) has responsibility for coal leasing on approximately 570 million acres where the coal mineral estate is owned by the Federal Government. The surface estate of these lands could be controlled by BLM, the United States Forest Service, private land owners, state land owners, or other Federal agencies. BLM receives revenues on coal leasing at three points: a bonus paid at the time BLM issues the lease; an annual rental payment of $3.00 per acre or fraction thereof; and royalties paid on the value of the coal after it has been mined. The Department of the Interior and the state where the coal was mined share the revenues.
Surface mines (sometimes called strip mines) are the source of about 65% of the coal that is mined in the US. These mining operations remove the soil and rock above coal deposits, or seams. Mountaintop removal and valley fill mining has affected large areas of the Appalachian Mountains in West Virginia and Kentucky. In this form of coal extraction, the tops of mountains are removed using explosives. As a result of this technique, the landscape is changed, and streams may be covered with rock and dirt. The water draining from these filled valleys may contain pollutants that can harm aquatic wildlife downstream. Although mountaintop mining has existed since the 1970s, its use became more widespread and controversial beginning in the 1990s.
Underground mines have less of an impact on the environment compared to surface mines. The largest impact of underground mining may be the methane gas that must be vented out of mines to make the mines a safe place to work. Methane is a strong greenhouse gas, meaning that on an equal-weight basis its global warming potential is much higher than other greenhouse gases. Surface mines contributed about 2% of total US methane emissions. The ground above mine tunnels can also collapse, and acidic water can drain from abandoned underground mines.
Using public lands for coal mining poses a significant threat to natural heritage. Coal mining dramatically alters the landscape, destroys wildlife habitat, causes erosion, and leads to the deterioration of drinking water.
Time For Changes
The ecological devastation from coal activities is disturbing. Action needs to be taken. Innovative technologies for improved mining and processing must be a priority to respond better to global environmental challenges, while governments and private sectors need to shift to alternative energy sources.
Water could be the key to finding life. There aren’t many qualities that are true of all life on Earth, but the need for water is one of them. It’s in all living things, whether they live at the bottom of the ocean or the driest desert. Water made life possible on Earth. Because of this, astrobiologists (scientists who search for life on other planets) think our best bet for finding life is to search for water.
Almost all Earth’s water is in the oceans. A whopping 96.5 percent of water on Earth is in our oceans, covering 71 percent of the surface of our planet. And at any given time, about 0.001 percent is floating above us in the atmosphere. If all of that water fell as rain at once, the whole planet would get about 1 inch of rain.
Most freshwater is in ice. Just 3.5 percent of Earth’s water is fresh—that is, with few salts in it. You can find Earth’s freshwater in our lakes, rivers, and streams, but don’t forget groundwater and glaciers. Over 68 percent of Earth’s freshwater is locked up in ice and glaciers. And another 30 percent is in groundwater.
The amount of salt in salt water varies. In a gallon of average ocean water, there is about 1 cup of salt. But it does vary. The Atlantic Ocean is saltier than the Pacific Ocean, for instance. Most of the salt in the ocean is the same kind of salt we put on our food: sodium chloride. The saltiest water in the world is found in Antarctica in a small lake named Don Juan Pond.
A lot can live in one drop of water. There can be a lot going on in a single drop of ocean water. It will most likely have millions (yes, millions) of bacteria and viruses. And it could also have fish eggs, baby crabs, plankton, or even small worms.
Some water may have come from comets. The rocky material that formed Earth contained some water. But that probably doesn't account for all the water we see today. Comets are mostly water ice. It’s possible that comets made regular water deliveries to Earth. It would take a lot of comets to fill the ocean, but comets could well have made a big contribution.
It’s really great that ice floats. Usually when solids form, atoms get closer together to form something denser. This is why most solids sink in water. But solid water, or ice, is actually less dense. This is unusual. The water molecules form rings when water freezes. All that space makes ice less dense. This is why it floats. This is great because ice floating on top of a body of water lets the rest of it stay liquid. If ice sank, whole oceans could freeze solid.
Our bodies are mostly water. A newborn baby is 78 percent water. Adults are 55-60 percent water. Water is involved in just about everything our body does. It’s a big part of the blood that brings nutrients to all our cells. We use it to get rid of wastes. It helps us regulate our body temperature. It acts as a shock absorber for our brain and spinal cord. We are very dependent on water.
In plants, water defies gravity. Water has an interesting characteristic. It’s sort of “sticky.” It likes to stick to itself and other things. That’s why water forms round droplets. Not all liquids do that. This “stickiness” helps get water from the roots of plants up to the leaves. Water molecules travel up thin straws called xylem in the plant by holding onto each other and the walls of the tube. They’re pulled upwards as water evaporates from the leaves at the top.
We get to see water in three different states, and that’s odd. We experience water in all three states: solid ice, liquid water, and gas water vapor. That’s actually pretty unusual. While all substances can be solid, liquid, or gas, a lot of them only change states at extreme temperatures. You probably don’t see liquid silver or solid oxygen very much because their melting points and freezing points are at temperatures that would kill us.
Our planet has a natural environment, known as ‘ecosystem’, which includes all humans, animals, plants, land and water. Human activities have caused much depletion and destruction of this ecosystem.
Environmentalism advocates the preservation, restoration and/or improvement of this natural environment by controlling pollution and protecting plant and animal diversity. Environmentalists attempt to balance relations between humans and the various natural systems on which they depend to achieve sustainability.
Earth advocates work to protect natural resources and ecosystems through education, activism and the political process. They seek to give the natural world a stronger voice in human affairs.
The environmental issues of today know no borders. We can't just put up fences around natural places to keep humans out. We must protect the entire planet for the survival of all species — plants, animals and people. Governments, businesses, communities and individuals must make better decisions to live in balance with nature. Through science, responsible planning, legislation and daily choices, we can ensure the survival of the ecosystem.
There are many ways you can help to save wild places and wild animals. Volunteer. Recycle. Install solar panels on your roof. Organize an event where you live. Change a habit. Help launch a community garden. Communicate your priorities to your elected representatives. The possibilities are endless! Do something nice for the earth, have fun, meet new people, and make a difference.
The world population is expected to reach 9 billion by 2050. As our population increases, there is even more pressure on forests, grasslands, deserts and other natural areas to provide food, housing and energy for humans. These demands increase the stress of already fragmented natural areas suffering from pollution, deforestation, disrupted migratory routes and changing environmental conditions.
Already, large numbers of people have been declared food-insecure; resulting in a land rush with nations hurrying to secure properties for agriculture and fuel crops. Forests are being cleared at alarming rates, an estimated 18 million acres each year. At the same time, poor agriculture practices lead to millions of acres of land lost annually through soil erosion and land degradation.
Trillions of tons of garbage is produced every year, while more and more goods are produced...resulting in the creation of more waste. Most garbage is buried underground in landfill sites, causing environmental and health concerns.
If we don’t make changes now, future generations will not experience the same plentiful, diverse planet that we know today.
Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog.
Air pollution is caused by polluters who refuse to clean up toxic air emissions, despite proven pollution control technologies. Most air toxics originate from human-made sources, including automobiles, factories, refineries and power plants. Indoor sources include building materials and cleaning solvents.
As the environment suffers, humans suffer from asthma, lung disease, heart ailments, cancer and shortened lives. Acid rain, often caused by pollutants in the atmosphere from automobile or industrial processes, falls from the sky in the form of rain, snow, fog or dry material. Devastating effects to forests, aquatic systems, buildings and human health can result. Air toxics then contaminate our food products, drinking water and soil.
Pollution, habitat fragmentation and destruction, and overfishing are having devastating effects on our oceans, rivers and lakes. Acidification, caused by increased carbon emissions, degrade coral reefs and corrode the shells of sea creatures. Freshwater ecosystems provide us with drinking water, food, energy and recreation. These ecosystems are also critical to plants and animals. Increased demands for food, energy and material goods have placed unprecedented pressure on these fragile environments. Within the next 20 years, half of the world’s population may face water shortages.
Oceans are a critical part of the earths support system. Acid rain pollutes our seas. Oceans are degraded by spills and chemical runoffs. The largest living structures on earth, coral reefs, are among the greatest storehouses of biodiversity on the planet. Up to 70 percent of coral reefs are expected to be lost by 2050 due to human activities.
Water is under threat from fertilizers and chemical runoff, dumped chemical and industrial wastes, untreated sewage and medicinal residues.
Genetic modification of plants and animals is a controversial subject, with many experts believing the ill impacts far outweigh the benefits to mankind. Manipulating plant DNA to produce super crops is a dangerous global experiment. When released into the environment, they cannot be recalled.
Genetically modified organisms (GMOs) can spread through nature and interbreed with natural organisms. They can contaminate natural environments in an unforeseeable and uncontrollable way. This is referred to as 'genetic pollution', a major threat to the environment.
Due to commercial interests, the public has been denied the facts about GMO ingredients in the food chain. The absence of labeling laws in many countries denies individuals the power to avoid them.
Biological diversity must be protected and respected. It is fundamental to our planet's survival.
The world's deserts are generally remote, inaccessible, and inhospitable. Hidden among them, however, are hydrocarbon reservoirs, evaporites, and other mineral deposits, as well as human artifacts preserved for centuries by the arid climate.
In these harsh environments, the information and perspective required to increase our understanding of arid-land geology and resources often depends on remote sensing methods. Remote sensing is the collection of information about an object without being in direct physical contact with it.
Remote sensing instruments in Earth-orbit satellites measure radar, visible light, and infrared radiation. Radar imaging systems provide their own source of electromagnetic energy, so they can operate at any time of day or night. Additionally, clouds and all but the most severe storms are transparent to radar.
The first Shuttle Imaging Radar System (SIR-A), flown on the U.S. space shuttle Columbia in 1981, recorded images that show buried fluvial topography, faults, and intrusive bodies otherwise concealed beneath sand sheets and dunes of the Western Desert in Egypt and the Sudan. Most of these features are not visible from the ground. The radar signal penetrated loose dry sands and returned images of buried river channels not visible at the surface. These images helped find new archeologic sites and sources of potable water in the desert. These "radar rivers" are the remnants of a now vanished major river system that flowed across Africa some 20 million years before the development of the Nile River system.
Radar imagery also is a powerful tool for exploring for placer mineral deposits in arid lands. In 1972, the United States launched the first of a group of unmanned satellites collectively known as Landsat. Landsat satellites carry sensors that record "light," or portions of the electromagnetic spectrum, as it reflects off the Earth. Landsat acquires digital data that are converted into an image.
The scarcity of vegetation makes spectral remote sensing especially effective in arid lands. Rocks containing limonite, a hydrous iron oxide, may be identified readily from Landsat Multispectral Scanner data. The Landsat Thematic Mapper (TM) has increased our ability to detect and map the distribution of minerals in volcanic rocks and related mineral deposits in arid and semiarid lands. More than a million images of Earth have been acquired by the Landsat satellites. A Landsat image may be viewed as a single band in blackand-white, or as a combination represented by three colors, called a color composite. The most widely used Landsat color image is called a false-color composite because it reproduces the infrared band (invisible to the naked eye) as red, the red band as green, and the green band as blue. Healthy vegetation in a false-color composite is red.
Around 4,000 years ago, someone in northern China came across an odd black rock. It was one of many. Then this person discovered something. Somehow this person discovered that the rock could burn.
Life was harder back then. Keeping warm and getting food were big worries. With no electricity or gas for heating or cooking, everyone burned wood. The strange rock that burned like a log must have been very exciting back then.
This rock was coal. Archeologists think this was the first time a human used a fossil fuel.
For many years, only a few places with easy access to coal used it. Outside China, one such place was Britain. It was hard to miss there. People could go to the beach and pick up lumps of coal. They called it “sea coal.”
During the years of Roman rule in the British isles, they used coal to heat water for the public baths. The Romans liked coal so much that they brought it back to Rome with them. Traces of British coal can be found all around the Roman ruins in Italy.
Before the late 1600s, coal was used mainly for things like smelting and blacksmithing. (Smelting is a process of heating the ore dug out of the earth to get out the metals.) There were no real factories. Things were made by hand without the help of machines. That all changed with the invention of the steam engine.
The first common steam engine was called the Newcomen engine. It was first built 1712. It changed the world forever. It was first used to drain mines, but over time it was used for many other things too. The steam engine made big factories possible. Then it was put into trains and ships, so it could help transport things. It even powered some early cars. The demand for coal skyrocketed.
This big change was called the Industrial Revolution. It began in Britain. It gradually spread over much of the rest of the world. It’s not by chance that Britain led the Industrial Revolution; it had so much coal. It was this very coal that drove Britain, and eventually the world, into the modern society we know today.
Oil: A Nice Ride through the Countryside
Early one August morning in 1888, Bertha Benz left home with her two sons on a 66-mile trip to visit her mother. She took a brand new car. She didn't tell anyone. That car just happened to be her husband’s Benz Patent-Motorwagen—the first true automobile.
This trip wasn’t really about visiting Bertha’s mother. Bertha was frustrated with her husband, Karl Benz. Karl had an incredible invention, but he hadn’t been doing a great job of letting people know about it. Before Bertha set out on this trip, Karl had only given short demonstration rides, and there was always a team of mechanics standing by.
Bertha’s trip was the first long-distance car ride ever attempted. It was a great success. Bertha acted as her own mechanic. She came up with makeshift brake pads. She cleaned all the fuel pipes. And, like anyone else on a long road trip, she had to fill up with gas. She did so by purchasing a fluid called benzene from a local pharmacy. This pharmacy became the world’s first gas station.
Petroleum is a liquid that comes from oil. We put it into our cars to make them run. Petroleum means “rock oil.” It comes from the remains of once-living organisms, just like coal.
People have used petroleum for different purposes throughout history. But petroleum wasn’t used very much until another invention came along—the internal combustion engine. In 1863, a man named Nikolaus Otto created the first successful engine of this kind. Unlike a steam engine, in Otto’s engine, the heat comes from igniting fumes from a petroleum liquid. The pressure from the heat moves pistons. This is pretty much how all gas-powered cars still work to this day.
Petroleum, Oil, Gas: What’s in a Name?
A lot of different names are tossed around for liquid fossil fuels. Do they all mean something different? Here’s a brief explanation:
Petroleum is a collection of liquids formed from once-living things. It is a mixture of chemicals that contains carbon and hydrogen. People can also refer to petroleum as crude oil and sometimes just oil.
But you can’t pour that black sludge of oil into a car. You need to get specific chemicals out of the oil. Gasoline is what we usually put into our cars. It is one set of chemicals (with a couple of other added ingredients).
Kerosene is another set of chemicals used to heat homes and to cook. It is also the main ingredient in jet fuel.
The process of removing these chemicals from the oil, called “cracking,” occurs at an oil refinery.
Gas: A Fuel of Many Uses
You can find natural gas near oil, coal, and other rocks. It comes from the same natural processes that make coal and oil. It, too, comes from once-living things.
Humans have known about natural gas for a long time. Around 500 BCE, people in China used bamboo shoots to transport natural gas. They used it to boil water. A famous historian wrote about natural gas between 100 and 124 CE. That’s 1,900 years ago. This person wrote about flames burning from the ground of present-day Iraq. But even though people knew about it, it didn’t catch on as a major fuel source for some time.
Today, natural gas is often used for cooking and heating homes. It is one of the most important sources of energy in the world.
People once considered natural gas a problem. It was explosive and dangerous. Most oil and coal operations just burned it. Now it is valuable. Natural gas is cleaner burning than either coal or oil. That means it causes less pollution. Many places have switched from burning coal to burning natural gas. That means many places want more of it.
Since more people want natural gas, people will get it however they can. One way to get natural gas is with something called hydraulic fracturing, or “fracking.” Fracking is expensive, but people want natural gas so much, they’ll use this method. Fracking involves injecting water, sand, and chemicals into rocks to break them apart. This releases natural gas. Fracking helps people increase the amount of natural gas we can get, but there are environmental concerns over fracking. People worry that these chemicals can get into drinking water.
The King Who Banned Coal
King Edward I of England tried to ban coal in 1306. The air was dark and polluted. The smoke from coal was too much; it was poisoning the city. The king banned coal. It may have been the first environmental law ever.
Coal was more popular than wood at the time. There wasn’t enough wood to go around. Many metal smiths, brewers, and other craftsmen used coal, even though it was against the law.
Things got worse after the steam engine was invented. The Industrial Revolution was happening. There was now lots of pollution. It caused acid rain, sickness, and even death. Air quality was one of the first environmental issues addressed in the USA and Britain. They passed laws to limit pollution, but not until 1955.
Besides the dark smoke, there’s another problem with burning fossil fuels. It’s the carbon dioxide, CO2, that gets released. We have known that gases in the air can trap heat since 1824. John Tyndall showed that CO2 warmed the Earth in 1860. Many people have tested it since then. Many of them worried about all the CO2 from burning fuel since humans were burning so many fossils fuels. It could be a problem.
But many people didn’t believe there was a problem. People didn’t think the climate could ever change and that people couldn't do anything to change the world’s climate. But they changed their minds when, in 1957, scientists began to take measurements of CO2 in the atmosphere. They saw that CO2 was rising. Scientists could prove that most of that rise was from humans because fossil fuels make CO2 with slight chemical differences compared to other CO2.
Global temperatures are rising, too. Almost all climate scientists agree that a big cause of that is the burning of fossil fuels. The warming could lead to rising sea levels, droughts, flooding, and more severe weather. It is a challenge that we will have to deal with in the coming years.
Fossil fuels form all the time, but that doesn’t mean that we won’t run out someday. It takes millions of years for coal, oil, and natural gas to form, and we are removing them much faster than that.
Think about it this way: The fossil fuels we have used over the past 200 years formed over the past 500 million years. It’s like we’re emptying a bathtub with a huge drain while refilling it with a tiny, slow drip. Even with the drip, the tub will still empty completely.
Some scientists think we are getting close to being halfway through all that fuel. It’s hard to know exactly how much remains because the technology we use to get these fuels from the ground is always changing. Still, no new inventions will get around the fact that, at some point, there will be no more fossil fuels left.
The Price of Success
Fossil fuels have changed the course of human history. Cars, airplanes, and other fossil-fueled inventions changed everyone’s life. Without fossil fuels, life would be very different.
All these good things come at a cost. The cost is pollution, the destruction of landscapes and natural habitats, oil spills in the ocean, and dangerous fracking chemicals in the ground. Global warming will be the biggest problem of all. Global warming will affect everyone on Earth.
There is still time for another chapter in this story. This chapter will be a turn away from fossil fuels. We will move toward sustainable, green energy. We need a new way to power the many improvements that fossil fuels have given us.
5,500 animals a day, 228 an hour, 4 every minute - red-tailed hawks, Arctic foxes and river otters, some of America's most magnificent wildlife....By the time you finish reading this, 8 more of these wild animals will have been gunned down, crushed in traps, or poisoned by an exploding cyanide landmine laid down by the USDA's rogue animal-killing program, Wildlife Services.
This little-known agency, a unit of the U.S. Department of Agriculture, is secretive for a reason: Its actions are incredibly, unacceptably and illegally brutal and inhumane to animals, from familiar wildlife to endangered species - and even people’s companion animals.
This agency has been killing as many as 3 million native animals every year - including coyotes, bears, beavers, wolves, otters, foxes, prairie dogs, mountain lions, birds and other animals - without any oversight, accountability or requirement to disclose its activities to the public. The agency contributed to the decline of gray wolves, Mexican wolves, black-footed ferrets, black-tailed prairie dogs, and other imperiled species during the first half of the 1900s, and continues to impede their recovery today.
No other government program does more every day to annihilate America’s wildlife than Wildlife Services. This rogue program does much of its dirty work far from the public’s view, so millions of animals disappear from our landscapes every year with little accountability.
Most of Wildlife Services’ killing is done on behalf of the livestock and agriculture industries, along with other powerful interests. The methods are gruesome, including aerial gunning, traps and exploding cyanide caps. Companion animals have also been inadvertently harmed.
Many of these animals are carnivores at the top of the food chain and have a tremendous benefit to overall ecosystem health. They include endangered species and, largely, animals that agribusiness interests consider undesirable - as well as many animals that aren’t intended targets of the agency.
The century-old Wildlife Services - which has reportedly killed 32 million native animals since 1996 - destroys these creatures on behalf of such interests without explaining to the public what it’s doing or where, the methods it’s using, on whose behalf it’s acting, or why. It frequently doesn’t even attempt to use nonlethal methods before shooting coyotes and wolves from airplanes, or laying out traps and exploding poison caps indiscriminately - including in public areas - without any rules.
Stories about Wildlife Services consistently emerge describing an agency that routinely commits extreme cruelty against animals, leaving them to die in traps from exposure or starvation, attacking trapped coyotes, and brutalizing domestic dogs. Many people who know about the agency have criticized this dark, secretive entity as a subsidy for livestock interests.
As the actions of Wildlife Services continue to be exposed, organizations and individuals across the country continue to join together in an effort to end the inhumane slaughter of millions of animals each year by the federal government with taxpayers' money.
Life on Earth over the millennia has been defined by the evolution, survival and demise of multitudes of species. The churning of species is part of the life process and extinction is one inevitable component. But humans are now playing a large part in the extinction of many species.
Human activities are responsible for the significant changes in the world's environment. Human activities cause climate changes from industrial emissions and animal argiculture, destruction of wildlife habitat, reduced wildlife populations through hunting and poaching, and ecosystem disruption through pollution and litter. All these activities are major contributors to a serious decline in wildlife numbers.
Endangered Species Versus Threatened Species
Species of animals facing a high probability of becoming extinct in the future are categorized by conservationists and scientists as threatened. This kind of species is one whose existence in its natural habitat is at risk. The threat to its habitat could arise out of reasons like human developmental activities, climate change and introduction of foreign species.
Endangered species are those that are so extremely rare, and their population so low, that they are dangerously prone to extinction in the near future. The dangers they face are very similar to those faced by threatened species, the only difference being that the degree of threat is even higher given their low numbers and uniqueness of habitat. The risks of extinction here are much more.
The terms endangered and threatened species are often used interchangabley. When described in a general context, an endangered species is one that is faced with the threat of extinction but not necessarily protected by law. In a regulatory context, endangered species could come under a protective ambit when listed by bodies like US Endangered Species List and International Union for the Conservation of Nature (IUCN). The IUCN has a detailed and complete list of endangered species that it calls the Red List. The Red list has been graded into categories based on the degrees of risk to their survival ranging from safe to complete extinction.
Least Threatened: Species that face no immediate threat of extinction.
Near-threatened: Species in this category could possibly face threats in the foreseeable future.
Vulnerable: Species in this category could come under threat of extinction in the medium term.
Endangered: Species of animals facing a high probability of becoming extinct in the immediate future.
Critically Endangered: Species that are extremely rare and whose population are very few and on the decline and could become extinct anytime soon.
Extinct In The Wild: No populations of such species exist in the wild and they survive and thrive only in captivity.
Extinct: These species are no longer found anywhere on earth, either in the wild or in captivity.
The usage of different terms used by the IUCN is to highlight the level of risk faced by a particular species at a given point of time, which is, presently. Such grades enable conservationists and scientists to study the degree of threat a particular species may be under and direct their conservation efforts accordingly. One of the main objectives of the IUCN's list is to emphasize the plight of the critically endangered species and create the groundwork for saving such species from the threat of complete extinction. Simply put, the list's trend leading from Least Threatened to Extinction is an enabler for conservationists to prioritize their efforts accordingly.
Frequently Asked Questions
What is the US Endangered Species Act (ESA)?
Enacted into a law in 1973 during President Richard Nixon's tenure, the ESA is administered by the US Fish & Wildlife Service and NOAA Fisheries. Its objective is to protect endangered plant, animal and aquatic species through conservation of the habitats such species survive on.
How can I get a copy of the US Endangered Species Act?
A PDF version of the US Endangered Species Act can be obtained from the US Fish & Wildlife Service website.
How do rare animals make it to the Endangered Species List?
The authorities concerned adopt certain formal steps while ascertaining levels of threats to a certain species before declaring it to be endangered.
How do you find out which animals are on the Endangered Species List?
The Threatened and Endangered Species System (TESS) website maintains an up-to-date list and information of endangered wildlife species. This site is maintained by the US Fish & Wildlife Service and NOAA.
What endangered animals are in my state?
In addition to the Federal list, most states have their own lists of endangered species of animals. A knowledge of such species close to your home will help you make important lifestyle choices in their protection and conservation. A web search of your state's endangered species legislation can be helpful.
How can I contribute to conservation efforts of endangered species?
Rapidly reducing habitats pose a serious threat to the survival of the world's wildlife. Agencies and organizations may have chapters close to your home. Simple lifestyle changes such as reduced consumption, recycling, refraining from littering and polluting, and adopting a vegan diet go a long way in helping endangered wildlife.
Hunting is a major threat to wildlife, particularly in tropical regions. An international team of ecologists and environmental scientists have found that bird and mammal populations are reduced within 7 and 40 km of hunters' access points, such as roads and settlements.
Within these impact zones, mammal populations decline on average by 83%, and bird populations by 58%. Additionally, commercial hunting has a higher impact than hunting for family food, and hunting pressure is higher in areas with better accessibility to major towns where wild meat can be traded.
Only 17 percent of the original mammal abundance and 42 percent of the birds remain in hunted areas.
There are several drivers of animal decline in tropical landscapes: habitat destruction, overhunting, fragmentation, etc.
Higher hunting pressure occurs around villages and roads. Scientists have discovered that humans gather resources in a circle around their village and in the proximity of roads. As such, hunting pressure is higher in the proximity of villages and other access points. From there the densities of species increase up to a distance where no effect of hunting is observed.
Mammals are more sought after because they are bigger and provide more food. They are worth a longer trip. The bigger the mammal, the further a hunter would walk to catch it.
With increasing wild meat demand for rural and urban supply, hunters have harvested the larger species almost to extinction in the proximity of the villages and they must travel further distances to hunt. For commercially interesting species such as elephants and gorillas, hunting distances are even larger because the returns are higher.
Protected areas are no safe haven. Mammal populations have been reduced by hunting even within protected areas.
Strategies to reduce hunting in both protected and unprotected ecosystems are urgently needed to avoid further defaunation, including monitoring hunting activities by increasing anti-poaching patrols and controlling overexploitation via law enforcement.
Habitat destruction is the process in which natural habitat is rendered unable to support the species present. In this process, the plants and animals which previously used the site are displaced or destroyed, reducing biodiversity.
Habitat destruction by human activity is mainly for the purpose of harvesting natural resources for industry production and urbanization.
Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging, trawling and urban sprawl.
PRIMARY CAUSE OF EXTINCTION
Habitat destruction is currently ranked as the primary cause of species extinction worldwide. It is a process of natural environmental change that may be caused by habitat fragmentation, geological processes or by human activities such as the introduction of invasive species, ecosystem nutrient depletion and other human activities.
In the simplest terms, when a habitat is destroyed, the plants, animals, and other organisms that occupied the habitat have a reduced carrying capacity so that populations decline and extinction becomes more likely. Perhaps the greatest threat to organisms and biodiversity is the process of habitat loss. Organisms with limited ranges are most affected by habitat destruction, mainly because these organisms are not found anywhere else within the world and thus, have less chance of recovering. Many have very specific requirements for their survival that can only be found within a certain ecosystem, resulting in their extinction. Habitat destruction can also decrease the range of certain organism populations. This can result in the reduction of genetic diversity and perhaps the production of infertile youths, as these organisms would have a higher possibility of mating with related organisms within their population, or different species.
Biodiversity hotspots are chiefly tropical regions that feature high concentrations of endemic species and, when all hotspots are combined, may contain over half of the world’s terrestrial species. These hotspots are suffering from habitat loss and destruction. Most of the natural habitat on islands and in areas of high human population density has already been destroyed. Islands suffering extreme habitat destruction include New Zealand, Madagascar, the Philippines, and Japan. South and east Asia—especially China, India, Malaysia, Indonesia, and Japan—and many areas in West Africa have extremely dense human populations that allow little room for natural habitat. Marine areas close to highly populated coastal cities also face degradation of their coral reefs or other marine habitat. These areas include the eastern coasts of Asia and Africa, northern coasts of South America, and the Caribbean Sea and its associated islands.
Regions of unsustainable agriculture or unstable governments, which may go hand-in-hand, typically experience high rates of habitat destruction. Central America, Sub-Saharan Africa, and the Amazonian tropical rainforest areas of South America are the main regions with unsustainable agricultural practices or government mismanagement.
Areas of high agricultural output tend to have the highest extent of habitat destruction. In the U.S., less than 25% of native vegetation remains in many parts of the East and Midwest. Only 15% of land area remains unmodified by human activities in all of Europe.
Tropical rainforests have received most of the attention concerning the destruction of habitat. From the approximately 16 million square kilometers of tropical rainforest habitat that originally existed worldwide, less than 9 million square kilometers remain today. The current rate of deforestation is 160,000 square kilometers per year, which equates to a loss of approximately 1% of original forest habitat each year. Other forest ecosystems have suffered as much or more destruction as tropical rainforests. Farming and logging have severely disturbed at least 94% of temperate broadleaf forests; many old growth forest stands have lost more than 98% of their previous area because of human activities. Tropical deciduous dry forests are easier to clear and burn and are more suitable for agriculture and cattle ranching than tropical rainforests; consequently, less than 0.1% of dry forests in Central America's Pacific Coast and less than 8% in Madagascar remain from their original extents.
PLAINS & DESERTS
Plains and desert areas have been degraded to a lesser extent. Only 10-20% of the world's drylands, which include temperate grasslands, savannas, and shrublands, scrub and deciduous forests, have been somewhat degraded. But included in that 10-20% of land is the approximately 9 million square kilometers of seasonally dry-lands that humans have converted to deserts through the process of desertification. The tallgrass prairies of North America, on the other hand, have less than 3% of natural habitat remaining that has not been converted to farmland.
Wetlands and marine areas have endured high levels of habitat destruction. More than 50% of wetlands in the U.S. have been destroyed in just the last 200 years. Between 60% and 70% of European wetlands have been completely destroyed. About one-fifth (20%) of marine coastal areas have been highly modified by humans. One-fifth of coral reefs have also been destroyed, and another fifth has been severely degraded by overfishing, pollution, and invasive species; 90% of the Philippines’ coral reefs alone have been destroyed. Finally, over 35% mangrove ecosystems worldwide have been destroyed.
Habitat destruction caused by humans includes conversion of land to agriculture, urban sprawl, infrastructure development, and other anthropogenic changes to the characteristics of land. Habitat degradation, fragmentation, and pollution are aspects of habitat destruction caused by humans that do not necessarily involve overt destruction of habitat, yet result in habitat collapse. Desertification, deforestation, and coral reef degradation are specific types of habitat destruction for those areas (deserts, forests, coral reefs).
The forces that cause humans to destroy habitat are known as drivers of habitat destruction. Demographic, economic, sociopolitical, scientific and technological, and cultural drivers all contribute to habitat destruction.
Demographic drivers include the expanding human population; rate of population increase over time; spatial distribution of people in a given area (urban versus rural), ecosystem type, and country; and the combined effects of poverty, age, gender, and education status of people in certain areas.
Most of the exponential human population growth worldwide is occurring in or close to biodiversity hotspots. This may explain why human population density accounts for 87.9% of the variation in numbers of threatened species across 114 countries, providing evidence that people play the largest role in decreasing biodiversity. The boom in human population and migration of people into such species-rich regions are making conservation efforts not only more urgent but also more likely to conflict with local human interests. The high local population density in such areas is directly correlated to the poverty status of the local people.
FEEDBACK & INTERACTIONS
There are also feedbacks and interactions among the proximate and underlying causes of deforestation that can amplify the process. Road construction has the largest feedback effect, because it interacts with—and leads to—the establishment of new settlements and more people, which causes a growth in wood (logging) and food markets. Growth in these markets, in turn, progresses the commercialization of agriculture and logging industries. When these industries become commercialized, they must become more efficient by utilizing larger or more modern machinery that often are worse on the habitat than traditional farming and logging methods. Either way, more land is cleared more rapidly for commercial markets. This common feedback example manifests just how closely related the proximate and underlying causes are to each other.
We are all becoming increasingly familiar with the impacts of invasive species. Knotweed from Japan can destroy building foundations, zebra mussels from eastern Europe can clog-up drinking water pipes, and an Asian fungus is causing ash tree die-back in our forests. Our rapidly changing world will bring new types of invaders, often from very unexpected places.
Invasive non-native species are among the greatest drivers of biodiversity loss on the planet. An international team of scientists identified that environmental change, new biotechnology and even political instability are all likely to result in new invasions that we should all be worried about.
Globalization of the Arctic, emergence of invasive microbial pathogens, advances in genomic modification technology, and changing agricultural practices were judged to be among the 14 most significant issues potentially affecting how invasive species are studied and managed over the next two decades.
Globalization Of The Arctic
Until now, the Arctic has been among the least accessible regions on the planet, escaping extensive alien species invasions like those that have affected temperate and tropical areas of the world. However, the rapid loss of sea ice is opening the region to shipping, oil and mineral extraction, fishing, tourism, and shoreline development -- all of which facilitate introductions of alien species.
The loss of sea ice is also creating a major new corridor for international shipping between the Pacific and Atlantic Oceans, which will affect invasion risks throughout the Northern Hemisphere. The gold rush has begun for major expansion of human activities in the Arctic, with the potential for large-scale alien species transfers.
Emergence & Spread Of Invasive Microbial Pathogens
Disease-causing bacteria, water molds, fungi and viruses are being given increasing opportunities to spread into regions where they never previously existed and where they may attack new hosts. They can also undergo rapid genetic changes that cause previously innocuous forms to become virulent.
Invasive microbes have devastated populations of animal and plants that have had no evolutionary exposure and thus no immunity to them. Recent examples include: the chytrid fungus "Bsal" that is killing salamanders in Europe; the white-nose fungus that is destroying bat colonies in North America; and sea star wasting disease along the Pacific coast of North America, considered to be among the worst wildlife die-offs ever recorded. The proliferation of microbial pathogens is a burgeoning threat to biodiversity, agriculture, forestry and fisheries.
Biotechnological Advances & Applications
Advances in genomic modification tools hold both promise and challenges for managing invasive species. Very recently, genetically modified versions of an invasive mosquito were released in the Florida Keys in a controversial attempt to interfere with the mosquito's reproductive life cycle, thereby preventing it from vectoring the spread of invasive Zika, Dengue and Chikungunya viruses to humans. The push to use genetically modified agents to control invasive species will continue to grow, and with it will come public opposition and the view that we are opening Pandora's Box.
Changing Agricultural Practices
Changing agricultural practices are also a potential source of invasion threats. Virtually unregulated new agricultural crops and practices open the door to potentially disastrous unintended consequences. An Asian cricket species reared for "cricket flour" -- all the rage in the USA -- has already established in the wild. Worse, as a disease ravages this species, farmers have imported other kinds of crickets that might well invade in nature.
But possibly the biggest threat of all is the growing use by agribusiness of soil bacteria and fungi to increase crop production. The cultivation and distribution of 'growth enhancing' microbes could cause some crop plants or plant species residing near agricultural fields to become invasive pests.
Always turn off lights when you leave the room, unless... You should always turn off the light when you leave a room. This can save a lot of energy. But if you have special light bulbs called CFLs, you don't always have to turn them off. Turning them on and off too many times shortens their lifespans. You should turn them off if you'll be gone for 15 minutes of more. If you'll be right back, you can leave them on.
Coal is king, but not everywhere. In the United States, coal makes 39% of our electricity. It's burned in a power plant, and the heat is used to boil water. The steam moves a turbine and generates electricity. In West Virginia, over 90% of the electricity is generated from coal. But in California, only 1% of electricity is generated from this fossil fuel.
Daylight saving time is good for the planet. When we turn our clocks forward each spring, we move an hour of daylight toward the end of the day. In 2008, we had four extra weeks of Daylight Saving Time. Scientists studied how much energy we saved. Turns out, we saved 0.5% of electricity. Even though that sounds small, it's actually 1.3 billion kilowatt-hours. That's how much electricity 100,000 houses use in a whole year.
Every state uses hydropower for electricity. A flowing river is powerful. We can use the flow to make electricity. Ancient Greeks built water wheels to grind grain thousands of years ago. Today, every state uses hydropower, which is electricity from the flow water. In Washington State, 70% of the electricity comes from hydropower. Hydropower plants are inside dams, like the Hoover dam. Some places don't build dams. They use just part of a river to make electricity.
The United States is a world leader in wind. Wind has been a source of renewable energy since the invention of the windmill thousands of years ago. Today's wind power is made from big wind turbines. They're over 300 feet tall. Some have 8,000 parts. Along with China, Germany, Spain, and others, the United States is using wind to make lots of electricity.
The first solar powered satellite is still in orbit. The sun gives us lots of energy everyday. It hits us with 10,000 times the world's total energy use. The space industry has used solar power since the 1960s. It's great for spacecraft. Vanguard 1 was the first spacecraft to use solar cells. It's the oldest artificial satellite still in orbit around Earth.
We can get energy from trash. All that waste we flush down the toilet and put in our trashcans doesn't have to go to, well, waste! When waste breaks down, it can release methane, a natural gas. We can trap that gas and use it to make electricity. This is also helpful because methane is a greenhouse gas. If we use it, we keep it out of the atmosphere. This is great for the environment.
Electric vehicles are great, but not everywhere. Cars that run on electricity instead of gas don't release pollution. But when you charge the car at home, where does that electricity come from? If the electricity comes from renewable sources, electric cars are great for the environment. But if you charge a car with electricity made from coal, it's not as good. The car doesn't pollute, but the power plant that charges that car does.
We need better batteries. You might be surprised, but batteries need a lot of work. They don't store enough energy. For us to use solar power and wind power, we need to be able to store a lot of energy. That way, we can still have electricity on cloudy days with no wind. Lots of researchers are working to make better batteries that last longer and hold more energy.
We measure energy in BTUs. When we talk about energy, we all need to use the same unit to compare numbers. Just like we might use feet or meters to talk about length, we need a unit for energy. The standard unit of energy is called the BTU. That stands for British Thermal Unit. It's the amount of energy needed to raise the temperature of a pound of water by one degree Fahrenheit. When you burn a four-inch kitchen match, it releases about 1 BTU of energy.
While it's quite common to keep parrots and toucans as “pets” for human entertainment, they are creatures of the wild and not meant to be caged. Thousands of these birds are still taken away from their families and flocks every year, packed up as if they were toys and sold at bird shows, through pet shops, or peddled on the internet. Many don't survive the journey, and those who do are likely to be destined for a life of misery. As a result of the demand, populations in the wild have suffered immensely, compounded by deforestation, animal agriculture, hunting and logging. Some species have been completely wiped out from parts of their range.
These birds are often stolen from the wild illegally and falsely declared as captive bred. They are then laundered into the global wildlife trade, often “legalized" along the way. The illicit pet trade industry is believed to have contributed to the threatened status of 66 parrot species and the extinction of the Spix’s Macaw. Nearly 27 percent of worldwide parrot species are now at risk.
Whether wild caught or captive bred, a birds' instinctive yearning to fly is thwarted when they are confined to a cage. Exotic birds are not "domesticated" even when they are bred in captivity; they retain their wild needs and instincts. Even in a large aviary, it is virtually impossible to provide birds in captivity with a natural existence, since naturally changing temperatures, food, vegetation, and landscape cannot be recreated indoors, nor, of course, can the birds fly freely.
There are nearly 390 species of parrots with habitats spanning from the Tropic of Cancer downwards to virtually all the countries in the Southern hemisphere. Though the primarily color of the parrot is green, there are multi-colored species – especially found in the deep jungles of Papua New Guinea.
Toucans are distinguishable from the parrot by their large and colorful bills. Their geographical spread of habitat is much narrower than the parrot, being restricted to the Amazon region of Brazil and North-eastern parts of the South American continent and the jungles of the Caribbean.
Illegal trafficking in parrots is quite common in India, despite the activity being banned by the authorities since 1991. Smuggling three to four week old chicks is rampant, threatening what is left of the 12 species of the bird left in the wilds of the country. Many of the birds die en-route to their chosen destinations. The plum-headed, red-breasted, malabar, Himalayan and Finsch’s parakeets are some of the threatened Indian parrot species.
Most vulnerable are island parrots. Rapidly growing human habitations and limited land space are squeezing out forest areas, and consequently the parrots. There are just 800 St. Vincent parrots left on the Caribbean island of St. Vincent. The Society islands of the Pacific are home to a dwindling population of a parrot species known as blue lorikeets, of which just 2,000 are left.
In the Amazon, common threats afflicts all wildlife - deforestation, growing farmlands and rampant logging. Diminishing food sources, and a lucrative illicit trade, have reduced one of the largest and most colorful species of parrot to near extinction. The Lear’s macaw was one of the most commonly found birds in the Amazon forests, but now is ensconced in a small patch of forest in the North-eastern Brazilian state of Bahia. There are only 960 of these birds that have been declared critically endangered. Parrot protection groups have gone to the extent of purchasing 4,000 acres of forest in the region to be under protection as suitable habitat to these rare birds.
Even worse is the fate of the blue-throated macaw of Bolivia, a victim of extensive mining activity, forest farming and illegal trade. Their absolute paltry numbers, just around 87, have prompted a captive breeding program desperately attempting to save these rare Bolivian birds.
Species like the thick-billed parrots were hunted to the point of extinction in Arizona. They are found across the border in Mexico where they presently face the twin threats of logging and illegal pet trade. Thick-billed parrots depend on their natural habitats of mature pine forests for their food source. Since such forests are vanishing fast, the birds are being driven out to drier desert regions where they simply cannot last long.
Among the most fascinating and loved of feathered animals in the world are the parakeets, or lorikeets. Wild parakeets inhabit the thick mountainous jungles of Papua New Guinea, the forest regions of Northern Australia, and the Polynesian islands in the Pacific. A combination of dazzlingly different colors and vocal variations make them the most sought after creatures by zoos of the world, and as pets doomed to life in captivity. Despite being protected in the still vast virgin tropical forest tracts of the Australasia region, their remarkable traits and appearance still make them targets of illegal trade. The budgerigar is one such species of lorikeet which has been in great demand as “pets” for decades.
The Australasia species also face a threat in the form of Proventricular Dilatation Disease (PDD). PDD causes regurgitation, a state in which food remains undigested in the digestive tract or blood. PDD is known to be caused by a virus called Bornavirus that results in weight-loss, feather-plucking, toe-tapping, and other issues.
The threat to toucans is not dissimilar to that of parrots. In fact, their much limited habitat and small number of species, just five, make their survival a much bigger threat. Loss of habitat due to deforestation, and wanton creation of farmlands especially in the Amazon, are common threats. The toucan is hunted for the rich fabric of its feathers that has great commercial value. The toucans fare even worse as pets than the parrots and can die from sheer desolation. Being deep forest birds, they are susceptible to diseases arising out of sudden human presence in their vicinity.
Parrots are more threatened than other bird groups. Loss and degradation of habitat, animal agriculture, hunting and the wildlife trade are all threatening the future of parrots and toucans. An alarming 56 percent decline of all parrot species is currently taking place. Action must be taken now to save these birds from being lost forever.
Although protected areas such as national parks can play a crucial role in conserving wildlife, most species of large carnivores and large herbivores also depend on being able to occupy human-dominated landscapes. This sharing of space is often associated with conflicts between humans and wildlife, and between different groups of humans with divergent interests. In order to achieve a situation that can be described as "coexistence", there is a need to develop a more nuanced and realistic understanding of what this state looks like.
Recent research looks at ways to improve the ability of humans and carnivores to co-exist, which is crucial to carnivore conservation efforts around the world. Based on studies in areas as diverse as North America, Europe and Asia on species such as wolves, tigers, leopards, lynx and bears, researchers note that large carnivores need larger ranges than many protected areas afford. This means that carnivores often come in contact with human populations that are sometimes less than welcoming.
What actions could help mitigate the negative impacts of these contacts, allowing both humans and carnivores to more peacefully coexist in shared landscapes? Scientists suggest that mutual adaptations are key to success. Not only do wild animals have to behaviorally adapt to the presence of humans, but humans also have to adapt their behavior to the presence of wild animals.
Studies have shown that many species of large carnivores show an incredible ability to occupy heavily modified human-dominated landscapes. Many human societies also show a wide range of adaptations to the proximity of large carnivores. This includes changes to the way they farm and the adoption of cultural or religious practices to "negotiate" their relationship with their wild neighbors.
However, in many areas these adaptations have been lost, either due to a temporary absence of large carnivores or in the face of changing social-economic situations. The result is often severe conflicts of both an economic and social nature. Realizing the necessity of adaptation by both humans and the carnivores is a key first step towards transforming conflict to coexistence. Conservation efforts that fail to focus on both halves of the equation are doomed to fail.
A factor for success has to do with recognizing that a state of coexistence does not involve an idealized absence of conflict. Rather than trying to eliminate all risk, which can mean eliminating a species, we must explore ways to keep risks below tolerable levels. That involves understanding what factors influence tolerance.
While some communities may not tolerate any risks from carnivores, others may tolerate high risks because they attribute carnivores with ecological and cultural benefits that exceed those risks. In many communities, the priorities of various stakeholder groups are still sometimes at odds, and there is a reduced trust in authorities. Interventions such as new policies must take into account local concerns such as the adoption of novel decision-making strategies that give voice to varying viewpoints.
The challenges are surmountable through the help of community leaders, conservation organizations, and state or federal agencies. Insights from studies on coexistence can help reconcile debates about carnivore conservation in shared landscapes and advance broader discourses in conservation such as those related to rewilding, novel ecosystems, and land-sharing vs. land-sparing.
In many ways, large carnivores represent the ultimate test for human willingness to make space for wildlife on a shared planet. If it is possible to find ways to coexist with these species, it should be possible to coexist with any species.
Fifteen animal species are at the greatest risk of becoming extinct very soon. Expertise and money is needed to save them and other highly threatened species.
According to a recent study of highly threatened species, 841 endangered animal species can be saved, but only if conservation efforts are implemented immediately and with an investment of an estimated US $1.3 billion annually to ensure the species' habitat protection and management. For 15 species, the chances of conservation success are really low.
The 15 species with the lowest chances for survival in the wild and in captivity are:
Mount Lefo brush-furred mouse, Lophuromys eisentrauti, Cameroon
Chiapan climbing rat, Tylomys bullaris, Mexico
Tropical pocket gopher, Geomys tropicalis
Bay Lycian salamander, Lyciasalamandra billae, Turkey
Perereca Bokermannohyla izecksohni, Brazil
Campo Grande tree frog, Hypsiboas dulcimer, Brazil
Santa Cruz dwarf frog, Physalaemus soaresi, Brazil
Zorro bubble-nest frog, Pseudophilautus zorro, Sri Lanka
Allobates juanii, Colombia
Ash's lark, Mirafra ashi, Somalia
Tahiti monarch, Pomarea nigra, French Polynesia
Zino's petrel, Pterodroma madeira, Madeira
Mascarene petrel, Pseudobulweria aterrima, Reunion Island
Wilkins's finch, Nesospiza wilkinsi, Tristan da Cunha
Amsterdam albatross, Diomedea amsterdamensis, New Amsterdam (Amsterdam Island)
Their low chance for survival is due to high probability of their habitat becoming urbanized; political instability; and high costs of habitat protection and management.
The opportunity of establishing an insurance population in captivity for these 15 species is low, due to high costs or lack of breeding expertise for the species.
Although the cost seems high, safeguarding endangered species is essential if we want to reduce the extinction rate by 2020. When compared to global government spending on other sectors - e.g., US defense spending, which is more than 500 times greater - an investment in protecting high biodiversity value sites is minor.
In just the past 40 years, nearly 52 percent of the planet’s wildlife species have been eliminated. The leading cause of these shocking declines is irresponsible and unethical human activities. In addition to the devastating consequences of deforestation, animal agriculture, development, and environmental pollution, the wildlife trade is playing a major role in species extinction.
Poaching, which involves the illegal killing, hunting and capturing of wild animals for sale, is the biggest threat to wildlife after habitat destruction. Poaching is hunting without legal permission. The difference between poaching and hunting is the law.
Legal hunters also kill tens of millions of animals per year. For each of those animals, another animal is illegally killed. Whether done legally or illegally, all types of hunting have led to extinction of species. If not controlled, many more animals will be doomed to extinction.
In addition to their body parts, the animals themselves are in demand as exotic “pets”. There are around 5,000 tigers being kept as pets in the U.S., while only around 3,000 remain in the wild. Australia’s palm cockatoos, stolen from the wild, sell for tens of thousands of dollars on the black market.
Illegal wildlife trade generates up to 20 billion dollars each year, making it the fourth most lucrative illegal trade operation on the planet – just after drugs, human trafficking and the arms trade. The animals who fall victim to this trade are quickly becoming threatened and endangered. As their numbers drop, their value on the black market increases.
The rise in human population has been accompanied by rapid economic growth in some parts of the world. This growth has led to affluence and a huge and growing demand for animal by-products. China is now the largest importer of illegal wildlife. But poaching knows no boundaries. The United States is the second largest importer of illegal wildlife.
The exponential rise in illegal wildlife trade threatens to undo the decades of hard work by conservationists. Wildlife trade is now run by large international criminal syndicates with deep pockets and tentacles reaching into corrupt governments secretly abetting their activities. There are no available exact figures as to the size of this trade, but there are estimates that it could be as vast as $150 billion annually.
Iconic Species Being Hunted To Extinction
Some of the most common forms of poaching are the hunting and killing of elephants for their ivory, tigers for their skin and bones, and rhinoceros for the alleged medicinal value of their horns.
A huge surge in black market prices of ivory in China has led to heightened activity in elephant poaching in Africa. Over 30,000 elephants were killed in one year alone. The ban on ivory trade by virtually all African governments has done little to deter the poachers. In Tanzania, frenzied poaching has reduced the number of elephants from 100,000 in 2010 to just 44,000 presently. Poaching eliminated 48% of the elephant population in Mozambique during the last 5 to 6 years. Many of the local populace kill the animals for cash. Even militia groups are involved in the poaching of elephants.
The sub-Saharan black rhinoceros is now almost extinct by extensive poaching. There are only 4,000 of these animals left now, compared to the 100,000 that roamed the wilds not even half a century ago. An almost 7,700% rise in poaching of white and black rhinos has occurred in 9 years in South Africa. Rising affluence in Vietnam in the last decade has spiked the demand for rhino horns. Rhino horns are crushed into powdered form for its bogus medicinal value.
This is just one chapter of the sordid story. Millions of of animals, birds, plants and marine life are killed every year. Wildlife trade accounts for the killing or capture of 100 million tons of fish, 1.5 million living birds, and almost 450,000 tons of plants annually. The combined population of all species of wildlife on Earth has fallen by as much as 40% since the 1970's.
One rhino is poached every 8 hours. Rhino horns are more valuable than gold. They can sell for as much as $30,000 a pound. Gold is worth about $22,000 a pound. Rhino horns are believed to cure impotence, fever, hangovers, and even cancer, but they actually have no medicinal properties. Rhino horns are not true horns. They are an outgrowth of the skin, like human hair or fingernails. They have no more medicinal effect than chewing on your fingernails.
Around 100 African elephants are killed every day by poachers – one elephant every 15 minutes. Ivory is carved into jewelry, trinkets, utensils, and figurines. Heavily armed militias and crime networks use ivory profits for terrorism and war funding.
Asian elephants are also at risk. Only around 32,000 Asian elephants remain in the wild. Around 30 percent of the remaining population are inhumanely held prisoners in zoos, circuses, and roadside attractions for human entertainment and profit.
Lemurs are among the most endangered mammals on Earth. 90% of all lemur species are considered vulnerable, endangered or critically endangered. Hunting lemurs for meat is diminishing their populations, already decimated by deforestation and climate changes.
Logging, roads and migrations caused by wars have brought people within the habitats of gorillas. Subsistence hunting has quickly grown into an illicit commercial business of gorilla meat, served up as “bushmeat” to wealthy clientele. Gorillas are also killed for their body parts for folk remedies, and as “trophies”. Baby gorillas are poached and sold for up to $40,000 each. Less than 900 mountain gorillas survive in Africa due to poaching.
Musk deer populations in Afghanistan, Pakistan, Bhutan, India, Nepal and Myanmar have been nearly wiped out for their sacs that contain ingredients used in perfumes – despite a ban on musk from international trade.
Tigers are poached for their teeth, claws, and whiskers, believed to provide good luck and protective powers. Skins and bones are considered status symbols. One tiger can bring as much as $50,000 on the black market.
Up to half of Africa’s lions have been illegally killed in just 20 years. Only about 32,000 remain in the wild.
The sun bear as a species has been rendered almost extinct in its habitat in South-east Asia, Myanmar, Bangladesh and North-Eastern India. The gall bladders of these animals find use in medicines among the Chinese. A bear’s gallbladder can fetch more than $3,000 in Asia.
Poached sharks, manta rays, and sea cucumbers are used by Asian consumers to make shark fin soup. Over 11,000 sharks are killed every hour, every day.
The American black bear is one of the top 10 most endangered bears on the planet. While 34 states have banned the trade of black bear bile and gallbladders, poaching and legal hunting is killing almost 50,000 bears every year. Their gallbladders and bile are sold to treat diseases of the heart, liver, and even diabetes.
Over 28,000 freshwater turtles are poached daily – used for medicine, food and kept as pets. About 80 percent of Asia’s freshwater turtle species are now in danger of extinction.
The Sunda pangolin's population in its habitat in the jungles of Malaysia and Java, Indonesia has halved in the last fifteen years. Their meat fetches considerable demand as a luxury food among affluent Chinese, and their scales are sought for their medicinal properties.
Millions of Tokay geckos are poached every year from South-east Asia, the Philippines and Pacific islands for use in traditional medicine.
Despite being on the U.S. Fish and Wildlife Service’s Endangered List since 1998, bighorn sheep populations continue to dwindle. Their antlers sell for over $20,000 on the black market.
Poaching isn't limited to exotic and threatened species. Deer and other wildlife species are often hunted “out of season”. Millions of animals are killed every year.
These are a few of many cases which have come to light, while many cases of over-exploitation of species have gone unnoticed. Conservation efforts, and various laws banning the illegal trade in wildlife resources, have had little effect in deterring those involved in wildlife trade. Educating humans on the urgent need to conserve our wildlife resources also seems to be falling on deaf ears. Until consumers stop purchasing wild animal products, and governments make the issue more of a priority, the wildlife trade will continue to flourish.
Sand covers only about 20 percent of the Earth's deserts. Most of the sand is in sand sheets and sand seas vast regions of undulating dunes resembling ocean waves "frozen" in an instant of time. Nearly 50 percent of desert surfaces are plains where eolian deflation removal of fine-grained material by the wind has exposed loose gravels consisting predominantly of pebbles but with occasional cobbles. The remaining surfaces of arid lands are composed of exposed bedrock outcrops, desert soils, and fluvial deposits including alluvial fans, playas, desert lakes, and oases. Bedrock outcrops commonly occur as small mountains surrounded by extensive erosional plains.
Oases are vegetated areas moistened by springs, wells, or by irrigation. Many are artificial. Oases are often the only places in deserts that support crops and permanent habitation.
Soils that form in arid climates are predominantly mineral soils with low organic content. The repeated accumulation of water in some soils causes distinct salt layers to form. Calcium carbonate precipitated from solution may cement sand and gravel into hard layers called "calcrete" that form layers up to 50 meters thick.
Caliche is a reddish-brown to white layer found in many desert soils. Caliche commonly occurs as nodules or as coatings on mineral grains formed by the complicated interaction between water and carbon dioxide released by plant roots or by decaying organic material.
Most desert plants are drought-or salt-tolerant. Some store water in their leaves, roots, and stems. Other desert plants have long tap roots that penetrate the water table, anchor the soil, and control erosion. The stems and leaves of some plants lower the surface velocity of sand carrying winds and protect the ground from erosion.
Deserts typically have a plant cover that is sparse but enormously diverse. The Sonoran Desert of the American Southwest has the most complex desert vegetation on Earth. The giant saguaro cacti provide nests for desert birds and serve as "trees" of the desert. Saguaro grow slowly but may live 200 years. When 9 years old, they are about 15 centimeters high. After about 75 years, the cacti are tall and develop their first branches. When fully grown, saguaro are 15 meters tall and weigh as much as 10 tons. They dot the Sonoran and reinforce the general impression of deserts as cacti-rich land.
Although cacti are often thought of as characteristic desert plants, other types of plants have adapted well to the arid environment. They include the pea family and sunflower family. Cold deserts have grasses and shrubs as dominant vegetation.
Rain does fall occasionally in deserts, and desert storms are often violent. A record 44 millimeters of rain once fell within 3 hours in the Sahara. Large Saharan storms may deliver up to 1 millimeter per minute. Normally dry stream channels, called arroyos or wadis, can quickly fill after heavy rains, and flash floods make these channels dangerous. More people drown in deserts than die of thirst.
Though little rain falls in deserts, deserts receive runoff from ephemeral, or short-lived, streams fed by rain and snow from adjacent highlands. These streams fill the channel with a slurry of mud and commonly transport considerable quantities of sediment for a day or two.
Although most deserts are in basins with closed, or interior drainage, a few deserts are crossed by 'exotic' rivers that derive their water from outside the desert. Such rivers infiltrate soils and evaporate large amounts of water on their journeys through the deserts, but their volumes are such that they maintain their continuity. The Nile, the Colorado, and the Yellow are exotic rivers that flow through deserts to deliver their sediments to the sea.
Lakes form where rainfall or meltwater in interior drainage basins is sufficient. Desert lakes are generally shallow, temporary, and salty. Because these lakes are shallow and have a low bottom gradient, wind stress may cause the lake waters to move over many square kilometers. When small lakes dry up, they leave a salt crust or hardpan. The flat area of clay, silt, or sand encrusted with salt that forms is known as a playa. There are more than a hundred playas in North American deserts. Most are relics of large lakes that existed during the last Ice Age about 12,000 years ago. Lake Bonneville was a 52,000-square-kilometer lake almost 300 meters deep in Utah, Nevada, and Idaho during the Ice Age. Today the remnants of Lake Bonneville include Utah's Great Salt Lake, Utah Lake, and Sevier Lake. Because playas are arid land forms from a wetter past, they contain useful clues to climatic change.
Eolian processes pertain to the activity of the winds. Winds may erode, transport, and deposit materials, and are effective agents in regions with sparse vegetation and a large supply of unconsolidated sediments. Although water is much more powerful than wind, eolian processes are important in arid environments.
Wind erodes the Earth's surface by deflation, the removal of loose, fine-grained particles by the turbulent eddy action of the wind, and by abrasion, the wearing down of surfaces by the grinding action and sand blasting of windborne particles.
Most eolian deflation zones are composed of desert pavement, a sheetlike surface of rock fragments that remains after wind and water have removed the fine particles. Almost half of the Earth's desert surfaces are stony deflation zones. The rock mantle in desert pavements protects the underlying material from deflation.
Particles are transported by winds through suspension, saltation, and creep. Small particles may be held in the atmosphere in suspension. Upward currents of air support the weight of suspended particles and hold them indefinitely in the surrounding air. Typical winds near the Earth's surface suspend particles less than 0.2 millimeters in diameter and scatter them aloft as dust or haze.
Saltation is downwind movement of particles in a series of jumps or skips. Saltation normally lifts sand-size particles no more than one centimeter above the ground, and proceeds at one-half to one-third the speed of the wind. A saltating grain may hit other grains that jump up to continue the saltation. It may also hit larger grains that are too heavy to hop, but that slowly creep forward as they are pushed by saltating grains. Surface creep accounts for as much as 25 percent of grain movement in a desert.
Eolian turbidity currents are better known as dust storms. Air over deserts is cooled significantly when rain passes through it. This cooler and denser air sinks toward the desert surface. When it reaches the ground, the air is deflected forward and sweeps up surface debris in its turbulence as a dust storm. Crops, people, villages, and possibly even climates are affected by dust storms.
Most of the dust carried by dust storms is in the form of silt-size particles. Deposits of this windblown silt are known as loess. The thickest known deposit of loess, 335 meters, is on the Loess Plateau in China. In Europe and in the Americas, accumulations of loess are generally from 20 to 30 meters thick.
Small whirlwinds, called dust devils, are common in arid lands and are thought to be related to very intense local heating of the air that results in instabilities of the air mass. Dust devils may be as much as one kilometer high.
Wind-deposited materials hold clues to past as well as to present wind directions and intensities. These features help us understand the present climate and the forces that molded it. Wind deposited sand bodies occur as sand sheets, ripples, and dunes.
Sand sheets are flat, gently undulating sandy plots of sand surfaced by grains that may be too large for saltation. They form approximately 40 percent of eolian depositional surfaces. The Selima Sand Sheet, which occupies 60,000 square kilometers in southern Egypt and northern Sudan, is one of the Earth's largest sand sheets.
The Selima is absolutely flat in some places; in others, active dunes move over its surface. Wind blowing on a sand surface ripples the surface into crests and troughs whose long axes are perpendicular to the wind direction. The average length of jumps during saltation corresponds to the wavelength, or distance between adjacent crests, of the ripples. In ripples, the coarsest materials collect at the crests. This distinguishes small ripples from dunes, where the coarsest materials are generally in the troughs.
Accumulations of sediment blown by the wind into a mound or ridge, dunes have gentle upwind slopes on the wind-facing side. The downwind portion of the dune, the lee slope, is commonly a steep avalanche slope referred to as a slipface. Dunes may have more than one slipface. The minimum height of a slipface is about 30 centimeters.
Sand grains move up the dune's gentle upwind slope by saltation and creep. When particles at the brink of the dune exceed the angle of repose, they spill over in a tiny landslide or avalanche that reforms the slipface. As the avalanching continues, the dune moves in the direction of the wind.
A worldwide inventory of deserts has been developed using images from satellites and from space and aerial photography. It defines five basic types of dunes: crescentic, linear, star, dome, and parabolic.
The most common dune form on Earth and on Mars is the crescentic. Crescent-shaped mounds generally are wider than long. The slipface is on the dune's concave side. These dunes form under winds that blow from one direction, and they also are known as barchans, or transverse dunes.
Some types of crescentic dunes move faster over desert surfaces than any other type of dune. A group of dunes moved more than 100 meters per year between 1954 and 1959 in China's Ningxia Province; similar rates have been recorded in the Western Desert of Egypt. The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than 3 kilometers, are in China's Taklimakan Desert.
Straight or slightly sinuous sand ridges typically much longer than they are wide are known as linear dunes. They may be more than 160 kilometers long. Linear dunes may occur as isolated ridges, but they generally form sets of parallel ridges separated by miles of sand, gravel, or rocky interdune corridors. Some linear dunes merge to form Y-shaped compound dunes. Many form in bidirectional wind regimes. The long axes of these dunes extend in the resultant direction of sand movement.
Radially symmetrical, star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the high center of the mound. They tend to accumulate in areas with multi-directional wind regimes. Star dunes grow upward rather than laterally. They dominate the Grand Erg Oriental of the Sahara. In other deserts, they occur around the margins of the sand seas, particularly near topographic barriers. In the southeast Badain Jaran Desert of China, the star dunes are up to 500 meters tall and may be the tallest dunes on Earth.
Oval or circular mounds that generally lack a slipface, dome dunes are rare and occur at the far upwind margins of sand seas. U-shaped mounds of sand with convex noses trailed by elongated arms are parabolic dunes. Sometimes these dunes are called U-shaped, blowout, or hairpin dunes, and they are well known in coastal deserts. Unlike crescentic dunes, their crests point upwind.
The elongated arms of parabolic dunes follow rather than lead because they have been fixed by vegetation, while the bulk of the sand in the dune migrates forward. The longest known parabolic dune has a trailing arm 12 kilometers long.
Occurring wherever winds periodically reverse direction, reversing dunes are varieties of any of the above types. These dunes typically have major and minor slipfaces oriented in opposite directions.
All these dune types may occur in three forms: simple, compound, and complex. Simple dunes are basic forms with a minimum number of slipfaces that define the geometric type. Compound dunes are large dunes on which smaller dunes of similar type and slipface orientation are superimposed, and complex dunes are combinations of two or more dune types. A crescentic dune with a star dune superimposed on its crest is the most common complex dune.
Simple dunes represent a wind regime that has not changed in intensity or direction since the formation of the dune, while compound and complex dunes suggest that the intensity and direction of the wind has changed.
Humans dispose of trillions of tons of garbage every year. The average person in a developed country produces about 2.6 pounds of garbage every single day.
Landfills take in most of this garbage, while a substantial amount of litter finds its way into the natural environment. Tens of thousands of cans and bottles are thrown out of moving vehicles everyday. An enormous amounts of waste is left behind on beaches, parks and river banks. One clean-up drive alone along a US coastline collected over 3.5 million tons of garbage. A two-mile highway stretch of West Virginia yielded over 30,000 items of litter.
Imagine if that litter was being tossed into your home. For wildlife, this is the disturbing and dangerous reality of litter.
What is litter to us, unwittingly becomes food for hungry animals. This litter may seem useful to animals, but it is often harmful or deadly. Discarded foods are prone to quick contamination and the microorganisms that cause food poisoning can be fatal to animals.
Broken glass can cut the feet of wild animals, and unbroken bottles can be a death trap. Hungry animals in search of food remains at the bottom of a jar or can often get their heads stuck, causing fatal suffocation. Even the tiniest of creatures can be lured by something like a beer or soda can. The sharp edges of a discarded can can be a threat to such delicate creatures seeking shelter or a taste of what remains inside.
Highways have become deathbeds for many unwary animals foraging for food. Litter tossed out of car windows onto freeways attracts inquisitive deer, coyotes, raccoons and skunks. Foxes forage for garbage on our streets at night, followed by pigeons during the day feasting on the night's leftovers. In addition to the hazards posed by litter, these animals often suffer serious injuries or death from vehicle collisions.
Aquatic animals are among the worst affected by human litter. Trash tossed carelessly outside washes into storm drains and creeks, which empty into rivers that eventually flow to the oceans. Trash adversely affects the habitat of marine and other aquatic environments causing death and injury to seabirds, fish, marine mammals, turtles and countless other species through swallowing and entanglement. Fishing hooks are often injested by pelicans, turtles, seabirds and other aquatic creatures. Often, larger items like nets, fishing line, and abandoned crab pots snare or trap animals. Entanglement can lead to injury, illness, suffocation, starvation, and death. Seabirds suffer lead poisoning from ingesting small lead fishing weights. Seabirds have also moved inland to garbage dumps where they injest a variety of rubbish.
Plastic bags on the seafloor take 10 to 20 years to decompose. Plastic bottles take much longer. As a result, one piece can kill more than one animal. An animal killed by ingesting plastic will decompose long before the plastic, allowing the plastic to kill again.
Litter along our coastlines, much of it plastic, is often digested by seabirds, turtles and whales. Seagulls act as scavengers and consume litter from food leftovers on beaches. Serious consequences for these creatures include stomach and bowel damage, strangulation and death. Many more animals are ensnared by plastic six-pack holders.
Cigarette butt waste is not only unsightly, but when ingested may be hazardous to the health of animals. Cigarette butts are commonly discarded onto beaches, sidewalks, streets, parks and many other public places where domestic animals and wildlife may be exposed to risk of ingestion. When carelessly discarded, they are carried from storm sewers and beaches to streams, lakes and oceans. Sea creatures, birds and companion animals are indiscriminate eaters. Ingested cigarette butts can choke an animal or poison it with toxins. Animals may not be able to regurgitate such items, with some acquiring gastrointestinal bezoars that can lead to a false sense of satiation and subsequent under-nutrition.
Balloons are great at birthdays, weddings, graduations and more, but once they get loose, balloons can pose a threat to many animals. Birds, turtles and other wildlife commonly mistake balloons for food, which can harm or kill them. In addition, many animals become entangled in balloon strings, which can injury or even strangle them.
Attitudes towards litter management seem to be shifting towards the positive, albeit slowly. Landfills, the biggest receivers of garbage, have made some progress concerning the protection of wildlife. Improving package design and construction can reduce needless waste and render them less harmful to animals. But real change has to come from individuals. Recycling techniques adopted domestically can reduce outflow of litter from homes dramatically. Education on basic rudiments of garbage management and disposal at the domestic level can indeed go a long way in mitigating the threat to animals foraging for litter.
At the root of this growing hunger for trash lies the shrinking natural habitat of animals affected by unwarranted development. In the human quest for faster progress, the environment is the biggest casualty and animals are the victims. It is our responsibility to save animals from the hazards we have created. With the mountain of garbage being added daily to the earth's surface and seas by our teeming billions, a huge challenge faces us into the future.
WHAT YOU CAN DO
Fighting the litter problem begins at home.
- Cut back on the amount of trash you produce.
- Opt for reusable items instead of single-use products.
- Recycle as much of your trash as you can.
- Join local efforts to pick up trash.
- Keep streets, sidewalks, parking lots, and storm drains free of trash.
- Don’t litter. Common litter includes plastic bags, paper, candy wrappers, fast-food packaging, bottle caps, glass bottles, plastic six-pack rings and plastic straws.
- Spend one hour picking up litter. Organize a team of family, friends, or co-workers to pick up litter in your local neighborhood, wildlife refuge or park. Enjoy making a difference, getting exercise, getting to know people better and having cleaner surroundings.
- Don't host balloon releases. Encourage others to substitute balloons for other, more ecologically responsible, party favors.
Both the Arctic (North Pole) and the Antarctic (South Pole) are cold because they don’t get any direct sunlight. The sun is always low on the horizon, even in the middle of summer. In winter, the sun is so far below the horizon that it doesn’t come up at all for months at a time. So the days are just like the nights—cold and dark.
Even though the North Pole and South Pole are “polar opposites,” they both get the same amount of sunlight. But the South Pole is a lot colder than the North Pole. Why? Well, the Poles are polar opposites in other ways too.
The Arctic is ocean surrounded by land. The Antarctic is land surrounded by ocean. The ocean under the Arctic ice is cold, but still warmer than the ice. So the ocean warms the air a bit.
Antarctica is dry—and high. Under the ice and snow is land, not ocean. And it’s got mountains. The average elevation of Antarctica is about 7,500 feet (2.3 km). And the higher you go, the colder it gets.
Average (mean) temperature North Pole Summer: 32° F (0° C)
Average (mean) temperature South Pole Summer: −18° F (−28.2° C)
Average (mean) temperature North Pole Winter: −40° F (−40° C)
Average (mean) temperature South Pole Winter: −76° F (−60° C)
The Arctic ice is shrinking. If the ice were on a diet, we would say that it was very successful. But, just as with people on diets, shrinking too much is not healthy. The Arctic ice is shrinking because the ocean under the ice is warming. The warming ocean means Earth’s climate is getting warmer.
The Antarctic’s climate is also warming, but not as fast, because it is less affected by the warming ocean.
While some wildlife groups may use media attention to speculate that cats are causing species loss, leading biologists, climate scientists, and environmental watchdogs all agree: endangered species’ fight for survival rests in our own hands.
Focusing on cats diverts attention from the far more dangerous impact of humans. Too many media stories sidestep these realities to focus on sensational issues like cats’ imagined impact on birds. But cats have been a natural part of the landscape for over 10,000 years—that has not changed. What has changed in that time is how we have re-shaped the environment to suit 21st century human needs—at a great cost to the other species that share our ecosystem. Our direct impact on our environment is without a doubt the number one cause of species loss.
Make no mistake—habitat loss is the most critical threat to birds. With this exponential human population growth comes massive use of natural resources and rampant development: industrial activity, logging, farming, suburbanization, mining, road building, and a host of other activities. The impact on species from habitat destruction, pollution, fragmentation, and modification is alarming. According to the World Watch Institute, “people have always modified natural landscapes in the course of finding food, obtaining shelter, and meeting other requirements of daily life. What makes present-day human alteration of habitat the number one problem for birds and other creatures is its unprecedented scale and intensity.”
Human activities are responsible for up to 1.2 billion bird deaths every year. Nearly 100 million birds die annually from collisions with windows; 80 million from collisions with automobiles; 70 million from exposure to pesticides. Millions of birds are intentionally killed by U.S. government-sponsored activities each year.
The human population continues to grow, threatening other species. Exponential population growth has left little land untouched by human development. In America alone, the population grew by 60 million people between 1990 and 2010, and experts predict we will add 23 million more people per decade in the next 30 years. That kind of growth—the equivalent of adding another California and another Texas to our already teeming population—is unprecedented in American history.
Killing cats will not save wildlife. Studies have shown cats to be mainly scavengers, not hunters, feeding mostly on garbage and scraps. When they do hunt, cats prefer rodents and other burrowing animals. Studies of samples from the diets of outdoor cats confirm that common mammals appear three times more often than birds. Additionally, scientists who study predation have shown in mathematical models that when cats, rats, and birds coexist, they find a balance. But when cats are removed, rat populations soar and wipe out the birds completely.
Some wildlife organizations and media outlets continue to quote scientific studies that have been proven inaccurate. A careful analysis of the science concludes there is no strong support for the viewpoint that cats are a serious threat to wildlife.
Although human civilization and domestic cats co-evolved side by side, the feral cat population was not created by humans. Cats have lived outdoors for a long time. In the thousands of years that cats have lived alongside people, indoor-only cats have only become common in the last 50 or 60 years—a negligible amount of time on an evolutionary scale. They are not new to the environment and they didn’t simply originate from lost pets or negligent animal guardians. Instead, they have a place in the natural landscape.