Culminating five years of work, the U.S. National Climate Assessment was released this morning, offering a comprehensive review of observed and projected climate change. The amount of information contained within the report is vast, but below are some of the key images from its highlight document. They reveal a world and nation warming, poised to warm more, and the impacts playing out before our eyes.
1. The period from 2001-2012 was the warmest on record globally. Every year was warmer than the 1990s average.
2. The warming trend is unlikely due to changes in the sun’s output, which has not varied substantially as temperatures have risen.
3. U.S. temperatures have warmed 1.3-1.9 degrees since 1895, with most of the increase since 1970.
4. Precipitation events are trending heavier in the U.S.
5. Sea levels are rising, with some of the fastest rates (1-2 feet per century) in the Northeast.
6. Warmer ocean temperatures are leading to an increase in coral bleaching in tropical areas, in the U.S. and around the world.
7. The length of the frost-free season is growing.
8. The ragweed (pollen) season is expanding
9. Heating demand is decreasing, cooling demand is increasing.
10. Temperatures are projected to warm from a few to over 10 degrees by the end of the 21st century, depending on future greenhouse gas emissions.
11. The hottest days are projected to warm substantially.
12. Sea levels in the U.S. are projected to rise 1 to 4 feet depending on future greenhouse gas emissions and the rate of climate change
13. Warming is projected to reduce soil moisture in much of the West by several to 10-15 percent by the end of the century; how fast and how much depends on future greenhouse gas emissions
14. The projected increase in the frost-free season, days without precipitation and hot nights will impact agriculture.
15. Climate change significantly increases the risk of water supply stress by mid-century, especially in the western U.S.
Much more information is available on the report’s gateway Web site, which contains widely accessible, sharable, and highly interactive climate information: nca2014.globalchange.gov