Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
“If today is a typical day on planet Earth, we will lose 116 square miles of rainforest, or about an acre a second. We will lose another 72 square miles to encroaching deserts, as a result of human mismanagement and overpopulation. We will lose 40 to 100 species, and no one knows whether the number is 40 or 100. Today the human population will increase by 250,000. And today we will add 2,700 tons of chlorofluorocarbons to the atmosphere and 15 million tons of carbon. Tonight the Earth will be a little hotter, its waters more acidic, and the fabric of life more threadbare. The truth is that many things on which your future health and prosperity depend are in dire jeopardy: climate stability, the resilience and productivity of natural systems, the beauty of the natural world, and biological diversity.” David Orr, 1991 All life on Earth is part of one great interdependent system. Life (or biotic factors in our environment) interacts with the non-living (or abiotic factors in our environment) components of the planet. • atmospheric gases • oceanic waters • minerals and rocks • pH and salinity of the environment • non-living component in the soil Humanity depends totally upon this community of life, or the biosphere. Biodiversity is defined as the variety of the world’s organisms, including their genetic diversity and the many different forms each species takes. Biodiversity underscores planetary health and wellbeing. The greater the biodiversity, the healthier the ecosystem. There’s almost no end to the role plants play in the workings of our planet. Plants perform each of the following services, just to name a few: • Maintain a breathable atmosphere by giving off oxygen • Keep us cooler by providing shade and releasing moisture through their leaves • Prevent mud slides and flooding • Remove the main “greenhouse gas,” carbon dioxide, from the atmosphere When plant communities are damaged or destroyed, so too are important biological services that people and other living things depend on. Open your medicine cabinet and you’re likely to see a number of products derived from wild plants and animals. In fact, more than 25 percent of the medicines we rely on contain compounds derived from or modeled on substances extracted from the natural world. • The Pacific yew tree—once burned as trash in forestry operations— produces compounds found to be effective in treating ovarian, breast, and other types of cancers. • Animal-derived products are also important in medical treatments. For example, calcitonin, a hormone used for the treatment of osteoporosis, and protamine sulphate, an important medicine used in open-heart surgery, both come from salmon. But microorganisms may well be the best-represented species in medicine cabinets around the world: More than 3,000 antibiotics, including penicillin and tetracycline, were originally derived from these tiny life forms. As each of the above examples points out, all species—even those that seem “worthless,” like the Pacific yew, or microorganisms like fungi and bacteria—have the potential to provide us with useful or even life-saving products. • Sales of prescription drugs that contain ingredients extracted or derived from wild plants totaled more than $15 billion in the United States in 1990. Rosy Periwinkle: Anti-cancer agent Foxglove: Cardiac stimulant Common thyme: cures fungal infections Pineapple: Controls tissue inflammation Indian snakeroot: reduces high blood pressure Calisaya: (Quinine) antimalarial • Each year, more than 350 million people visit our national parks, and wildlife refuges. This visitation generates more than 400,000 jobs and more than $28 billion of economic activity. Bees, butterflies, birds, bats, and other animals pollinate 75 percent of the world’s staple crops and 90 percent of all flowering plants. • More than 40 crops produced in the United States, valued at approximately $30 billion per year, depend on insect pollination. • Certain types of bacteria make nitrogen available for use by crops, pastures, forests, and other vegetation…and in turn animals. Economists estimate that the value of this activity is $33 billion annually. Scientists say we're on the brink of the greatest global loss of biodiversity since the extinction of the dinosaurs and many other species more than 65 million years ago…the middle of an extinction event! Human activity is the cause. We're at risk of losing thousands of species in the future, in many cases because we simply don't recognize how our actions affect other living things. There’s nothing unnatural about the process of extinction or, for that matter, about disturbance to Earth’s ecosystems. The fact is that more than 99 percent of all species that ever existed have become extinct over a period of more than 3.5 billion years of evolution. Of course, the big difference between extinctions of the past and those of the present can be summed up in one word: HUMANS. Never before on our planet has one species been responsible for such a massive decline of global biodiversity. The loss of habitats—the places where organisms live and get the nutrients, water, and living space they need to survive—is the primary reason biodiversity is in decline. Habitat destruction can disrupt human communities as well as those of plants and animals. Dams on rivers in the Pacific Northwest have produced inexpensive electricity and have redirected water for agriculture—but they’ve also interrupted salmon migrations, The dams impede juvenile and drastically lowering the number adult migrations to and from the of salmon that reach their ocean by creating reservoirs. spawning grounds. • Less than one percent of North America’s original tallgrass prairie ecosystem remains. • More than one-half of the original wetlands in the United States have been lost or severely degraded in the last 300 years as a result of draining and filling. • More than 95 percent of the lower 48 states’ original primary forests are gone. The largest areas of primary forest are in the Pacific Northwest, where about 10 percent of the original forests remain. • The Yellowstone River is the only large U.S. river (longer than 600 miles) that is not severely altered by dams. • In Arizona, about 90 percent of river and stream habitat has been destroyed by dams, conversion to farmland, excessive pumping of groundwater, cattle grazing, and urban development. There is little doubt that our growing population will result in continuing habitat loss and will put enormous pressure on Earth’s natural resources. While some people argue that new technologies could indefinitely extend the use of nonrenewable resources and allow the use of alternative ones, many others feel that technology can only delay the time when the Earth loses its ability to sustain us. Karachi, Pakistan Population growth alone doesn’t account for the increasing consumption of natural resources that is largely responsible for biodiversity’s decline. Those of us living in affluent, industrialized nations consume a disproportionate amount of resources, including fossil fuels. Use of Endangered Animal parts • Tiger medicine. Leopard pelts. Armadillo purses. Alligator shoes. Each day, thousands of wild plants and animals are plucked from their natural habitats, converted into these and other products, traded in markets, and shipped across borders. Products made from endangered animals and plants come at a high ecological cost. Trade in endangered species is often restricted, so products that cost just a few dollars in a shop can cost hundreds or thousands of dollars in fines if they are brought back to the United States. For joint pain, for example, users of TCM have long turned to tiger bone, which they believe helps reduce swelling and suppress pain. Soil Erosion and Loss of Nutrients Plants grow in it. Pigs wallow in it. And termites build with it. Healthy soil supports a great part of life on Earth. That’s why scientists are concerned about soil erosion and the loss of nutrients caused by certain farming practices, cutting down forests, and building homes and roads. In the last 40 years, one-third of North America’s topsoil has washed off the land, and it’s ended up in waterways where it can cloud freshwater streams and smother incredibly diverse coral reefs. Supporting soil health and stability is key to sustaining productive farmland and a diversity of life for the future. Loss of Forests and Trees •From a cluster of pin oaks in a city park to tropical jungles of teak and mahogany, forests are the life support systems of the planet. They pump our air full of oxygen. They fortify our soils. They shelter, feed, and shade. And they house an amazing amount of plant and animal diversity. But in the past 200 years, many of the forests that once covered the planet have disappeared. Farms, houses, roads, and cities have sprung up in their place, along with imported species and whole plantations of just one kind of tree. MONOCULTURE Are There Enough Fish in the Sea? Shrimp. Lobster. Swordfish. Tuna. What do you think of when you hear these words? Marine biodiversity … or dinner? Fish have been a staple of the human diet for thousands of years. Most fisheries are in trouble because we’re catching fish and other marine species faster than they can reproduce. We’re also fishing in ways that destroy marine habitats and catch millions of “unwanted” creatures called bycatch, which are often tossed overboard, dead or dying. Shrimp trawl catch. The 95% of the catch in this photo that was not shrimp died on deck and was shoved overboard. This is called “bycatch” Environmental Toxins Bug spray. Powerful cleaners. Fertilizers for lawns, crops, and golf courses. These and other chemicals can help make our lives easier—but they can also cause unintended problems. Toxic chemicals have made their way into every ocean and continent on Earth and contaminated whales, panthers, seals, and almost every living thing, some very seriously. If they’re going to kill bugs, fungi, rodents, and weeds…what do you think they’ll do to you? Climate Change What’s the connection between polar bears and power plants, coral reefs and SUVs? Global warming. The use of fossil fuels for lighting our homes, driving our cars, and other activities is contributing to major changes in the Earth’s climate. It’s causing problems in every part of the world for all living things—including polar bears, coral reefs, migratory birds, plants, and people. What we need now, is cooperation from people everywhere, especially those of us in industrialized nations who “feast” the most on fossil fuels. Many people believe that biodiversity should be preserved not just because it is valuable to us in some way, but simply because it exists. People who hold this opinion believe that each species should be respected and protected because it is the product of many millions of years of evolution, and we have no right to interrupt the evolutionary process. Because we have the power to destroy species and ecosystems, humans have a moral obligation to be careful stewards of the Earth. Our children will inherit the planet with whatever biodiversity we pass on to them. The decisions we make as individuals and as a society today will determine the diversity of genes, species, and ecosystems that remains in the future.