While natural forces have influenced the earth’s climate, human-induced increases in atmospheric greenhouse gases from fossil fuels and land-use changes are now driving most of the observed warming. Temperature increases have already affected natural and human systems in many regions, and global temperatures will continue to rise for decades to come.
For the benefit of humanity, the American Geophysical Union and its network of Earth and space scientists are committed to studying climate change, its impacts and opportunities for adaptation, and to educating the public on what they learn.
- The Department of Commerce’s Bureau of Economic Analysis estimates at least one third of the U.S. Gross Domestic Product is weather and climate sensitive, a potential impact of $4 trillion a year.
- Since 1980, wildfire season in the Western U.S. has lengthened by 78 days.
- A NASA simulation that combined a modest 40-centimeter (ten-inch) sea-level rise by 2050 with storm surges from a Category Three hurricane found that, without new adaptive measures, large parts of New York City would be inundated, including much of southern Brooklyn and Queens and portions of lower Manhattan.
- Higher sea levels could affect the coastal zone in a variety of ways, including greater shoreline retreat and increased coastal erosion. Beaches are the leading tourist destination, with coastal states earning 85 percent of all U.S. tourism revenues.