“We can no longer avoid significant warming during this century,” Warren Washington, a senior scientist at the National Center for Atmospheric Research in Boulder, Colorado, said in a news release Tuesday announcing a new analysis of future climate scenarios churned out by supercomputers.
Left unchecked, global greenhouse gases are on track to reach concentrations of 750 parts per million in the atmosphere by 2100. This would push sea levels up 8.7 inches from thermal expansion; melt nearly all the Arctic sea ice; raise global temperature at least 4 degrees Fahrenheit; and cause dramatic shifts in rainfall patterns around the world, according to the analysis.
The good news is if nations cut greenhouse gases by 70 percent this century “we could stabilize the threat of climate change and avoid catastrophe,” Washington said. Sea levels, not counting melting ice sheets and glaciers, would rise just 5.5 inches; the Arctic ice would shrink another quarter but no more; temperature would rise a degree above current levels, and the worldwide precipitation changes would be half as severe.