The United States came in 61 out of 163 countries on the Environmental Performance Index. The index was compiled by researchers at Yale and Columbia universities. It took into account categories such as environmental health, air pollution, water, forestry, biodiversity and climate change.
The United States took hits for its air pollution impact on ecosystems and for climate change. It rated high for its water and air impact on humans and for forestry.
The top five ranking nations, in order, were Iceland, Switzerland, Costa Rica, Sweden and Norway. The bottom five were Togo, Angola, Mauritania, Central African Republic and Sierra Leone.