A team of researchers looks at the ecological impacts of a human population that's growing in more ways than one.
What are we eating and how much of the Earth's does it take? A new study breaks it down.
Wal-Mart announced today its goal to eliminate 20 million metric tons of greenhouse gas emissions from its global supply chain by 2015.
Last year half the world's emissions came from just 700 million people. Economists suggest that the wealthiest individuals are most to blame.