Scripps: The environmental damage caused by climate change isn't always immediate, but scientists say it's costing the U.S. a lot of money and problems right now.
New research reveals a sharp increase in global carbon-dioxide levels, passing 400 parts per million.
Dr. Pieter Tans is the lead scientist with the National Oceanic and Atmospheric Administration. He says greenhouse gas emissions reached a new benchmark.
"CO2 hasn't been this high in 800,000 years. This is very well known. And very likely,...