Aside from scientific measurements, climate change can be observed in nature's reaction to the warming atmosphere. One of the most alarming changes is the melting of polar ice caps, which has contributed to a rise in sea level. Scientists have also forecasted an increasing frequency of extreme temperatures, tropical cyclones, flooding, drought and wildfires. Some experts speculate that Hurricane Katrina of 2005 was caused in part by the increase in global warming--and is a sign of things to come.
Certain forms of life cannot adapt to rapid ecosystem changes brought about by global warming. The result has been the extinction of thousands of species and the endangerment of many more. According to the National Resources Defense Council (NRDC), arctic polar bears are vulnerable to melting sea ice, coral reef are beached by warming ocean waters and dissolving glaciers in Alaska have sent native seabirds into decline.
