The document discusses the impacts of global warming and climate change. It notes that average global temperatures have risen 0.74° Celsius since 1800 and are projected to increase by 1.8-4° Celsius in the next 50 years due to greenhouse gas emissions. Impacts include melting ice caps and glaciers, rising sea levels that could flood coastal cities by 2100, more droughts and forest fires, reduced food production, and increased disease. Stronger hurricanes and other extreme weather in recent years provide evidence that climate change impacts have already begun.