Global warming is affecting 300 million people and taking 300,000 lives per year, according to the first wide-ranging research on the impact of climate change. Released by former UN secretary general Kofi Annan's think tank, the study says floods, fires, storms, and heatwaves are costing the world more than $125 billion annually—and will kill up to half a million people per year by 2030.
The study also predicts widespread disease, poverty, and hunger, almost solely in developing regions, where mass migration and social instability will likely follow. Comparing effects on the world's rich and poor, the study says nations least at risk have promised only $400 million to help developing countries adapt. Annan's thinktank released the study as diplomats prepare for next week's UN climate change talks in Bonn. (Read more global warming stories.)