Human beings have changed the composition of the air itself â?? the global atmosphere â?? and something has to be done about it, UW-Madison professor Jonathan Foley told the state Natural Resources Board Tuesday on Earth Day.
“Between 1950 and 2000, the world population more than doubled. The economy grew sevenfold. Food consumption almost tripled. Water use roughly tripled. Fossil fuel use increased fourfold,” Foley said. “The planet started to notice.”
A long-term rise of carbon dioxide, methane and nitrous oxide â?? mainly due to the burning of coal, oil and natural gas â?? warmed the Earth, he said.