“Evidence for climate change abounds, from the top of the atmosphere to the depths of the oceans … The sum total of this evidence tells an unambiguous story: The planet is warming.”
From the National Climate Assessment draft report, released Jan. 11. A 60-member federal committee oversaw the development of the report, which included more than 240 authors in its creation. You can read and comment on the draft at ncadac.globalchange.gov.
1.5°F Average temperature increase in the U.S. since 1895
530 billion Tons of carbon dioxide the oceans have absorbed over the last 250 years
63% Decrease in total winter ice coverage of the Great Lakes since the early 1970s
8 Number of inches global sea level has risen over the past century
1 to 4 Range of feet sea level is projected to rise by 2100
5 million Approximate number of people in the U.S. who live within 4 feet of the local high-tide level
20% Current U.S. contribution to global emissions
Changes in number of frost-free days per season
The length of the frost-free season has increased nationwide, which means the growing season is also longer. This map shows the increases from 1991–2011 compared to 1901–1960. The first and last days of frost are defined as the first occurrence of 32 degrees in the fall and the last occurrence in spring. These changes could alter the nature of some ecosystems, as birds, animals, insects and plants respond to overall warming.
Percentage change in very heavy precipitation, 1958–2011
The map shows percent increases in the amount of precipitation falling in very heavy events. These are defined as the heaviest 1 percent of all daily events. As the globe warms, these heavy precipitation events will become more common.
Correction: In print, the maps were reversed.