Global climate change impacts in the United States are spelled out with renewed authority in a federal government report.

The report's key information has been well reported here and in Earth Under Fire and other books, but bears repeating in its straightforward language and up-to-date numbers.
Human activities have led to large increases in heat-trapping gases over the past century. The global warming of the past 50 years is due primarily to this human-induced increase. Global average temperature and sea level have increased, and precipitation patterns have changed.
Human “fingerprints” also have been identified in many other aspects of the climate system, including changes in ocean heat content, precipitation, atmospheric moisture, plant and animal health and location, and Arctic sea ice.
Temperatures could rise by 2-3 degrees F or more than 11 degrees will depend on how we manage our energy use and emissions. Lower emissions of heat-trapping gases will delay the appearance of climate change impacts andlessen their magnitude.
Unless the rate of emissions is substantially reduced, impacts are expected to become increasingly severe for more people and places.