Today the Intergovernmental Panel on Climate Change released its fifth assessment on climate change. The findings are not surprising but sobering nonetheless. Even if you don't have time to look over the whole report, I encourage you to read the "headlines" document linked below, which will give you a pretty good understanding of the findings of hundreds of scientists from around the world on the causes and effects of climate change.
http://www.ipcc.ch/news_and_events/docs/ar5/ar5_wg1_headlines.pdf
http://www.ipcc.ch/news_and_events/docs/ar5/press_release_ar5_wgi_en.pdf
http://www.climatechange2013.org/
http://www.ipcc.ch/news_and_events/docs/ar5/ar5_wg1_headlines.pdf
http://www.ipcc.ch/news_and_events/docs/ar5/press_release_ar5_wgi_en.pdf
http://www.climatechange2013.org/