The 10 Biggest Challenges
These gases, which trap heat in the atmosphere, could warm the world by an additional 2.7 to 8.1 degrees Fahrenheit by the year 2050. That could trigger massive droughts, floods and more killer tropical storms. As jungles vanish, 50 to 100 species go extinct every Mr day. In most cases, no one knows their names-because science never got a chance to identify them. It is the greatest rate of extinction since the end of the dinosaurs....