When the court lights flicker on at the U.S. Open, tennis stars shine under illumination designed to cut light pollution.

America's national parks face mounting threats-from climate change and overcrowding to funding cuts and privatization. Here's ...

As many as 100 countries sought caps on plastic production, powerful oil-producing nations like Saudi Arabia and the United States stood against them.

National parks in Arizona and Colorado – often vacation destinations for New Mexicans – are among the report's hot spots for ...