HISTORY OF GLOBAL WARMING

History of global warming

Signs of climate change are everywhere. Nineteen of the planet's 20 hottest years on record took place in the 1980s or after. Rivers and lakes are thawing earlier each spring. Animals and plants are moving to higher elevations. The Arctic is heating up twice as fast as anyplace else in the world and polar bears are going hungry. Pacific islands such as Tuvalu are in danger of being swallowed by the sea and becoming a modern-day Atlantis. If people don't slash the amount of greenhouse gas emissions being pumped into the atmosphere , experts predict the planet's average temperatures could rise anywhere from 3 to 9 degrees Fahrenheit over the next century, with devastating results. According to the National Resources Defense Council (NRDC), "Sea levels will rise, flooding coastal areas. Heat waves will be more frequent and more intense. Droughts and wildfires will occur more often. Disease-carrying mosquitoes will expand their range. And species will be pushed to extinction."

For years, scientists, politicians and others debated what role, if any, people played in global warming, but today there is consensus among the majority of the scientific community that humans are to blame for the accelerated rise in greenhouse gases. In February 2007.

Global warming will bring more extreme weather. Drought-prone areas will become drier and desertification will spread as higher temperatures squeeze more moisture from the soil. A 2007 United Nations Intergovernmental Panel on Climate Change report predicts that by 2020, between 75 and 250 million Africans will be vulnerable to water shortages caused by global warming. Additionally, as the world's glaciers—such as the Himalayas i

Climate change also poses a big threat to human health. Warmer temperatures could lead to an increase in heat exhaustion, respiratory problems and lung damage from higher concentrations of ground-level ozone, according to the U.S. Environmental Protection Agency (EPA). Higher temperatures will also put people at greater risk for certain infectious diseases, especially those that occur in warm regions and are transmitted by mosquitoes and other insects. "These 'vector-borne' diseases include malaria, dengue fever, yellow fever, and encephalitis.

" The report continues: "Large-scale migrations from Africa to Europe are already on the increase at least in part because climate change has made traditional livelihoods, from farming to fish

Over the last 425,000 years, the concentration of CO2 in the Earth's atmosphere has fluctuated between 175 ppm (parts per million) and 300 ppm. At the dawn of the Industrial Revolution, the amount was around 280 ppm. The current number is approximately 380 ppm—and rising. Scientists have identified 450 ppm as a critical tipping point and predict that exceeding this number could cause irreversible damage to the planet