Many scientific studies have confirmed that the temperature of the planet has increased as a result of an excessive amount of carbon dioxide and other greenhouse gases. Research indicates that, since 1900, the Earth already has warmed 1.8 degrees Fahrenheit (1 degree Celsius), as of 2011. Continued increases could lead to irreversible damage, scientists warn. What's more, the atmospheric ozone depletion linked to at least one type of greenhouse gas, chlorofluorocarbons, is already raising skin-cancer concerns in Australia and elsewhere.
The higher temperature of the planet is melting glaciers and ice sheets, and the additional water is causing sea levels to rise. According to the National Wildlife Federation, studies indicate that the global sea level has increased by approximately 8 inches since 1900 and that the rate of the increase is accelerating. The warmer temperatures also cause the ocean water to expand, taking up even more space. The research estimates that warming of 2 to 3 degrees Fahrenheit could raise sea levels by 3 feet by 2100, which would be high enough to destroy many coastal cities and displace millions of people all over the world.
The Earth's ecosystem and wildlife systems can be dramatically impacted by global warming. Polar bears are already losing their hunting grounds as the ice melts; many species of cold-water fish -- such as salmon and trout -- will go extinct as the ocean water heats up; and numerous aquatic ecosystems will collapse as rising temperatures lead to massive coral bleaching. Because of weather changes, larger and more numerous floods are predicted to increase erosion levels, which would reduce the quality of water and devastate aquatic habitats. The expected increase in droughts will stress and kill many forms of vegetation that cannot adapt to the changing environment, and thus many animals will lose their grazing or feeding lands. The droughts could dry up 90 percent of U.S. wetlands, which would eliminate crucial breeding habitats for geese, ducks and other migratory species.
The greenhouse effect can alter the weather, increasing the size and intensity of storms. Global warming will cause rainfall to be heavier, which increases flooding, and hurricanes will become larger, stronger and more numerous. Research indicates that, during this century, the maximum wind speeds of hurricanes will increase 2 to 13 percent and the rainfall rate of hurricanes will increase 10 to 31 percent.
The global warming caused by greenhouse gases will generate more extreme heat waves -- summer days will be hotter and urban areas will feel the heat more intensely as the concrete and asphalt absorbs and re-radiates the heat. The longer and drier droughts in places such as the southwestern U.S. will drastically diminish water supplies, inhibit agriculture and cause more wildfires that are larger in size, more powerful and thus capable of causing more destruction. Additionally, winter is already becoming milder and shorter on average, and this trend is likely to continue.