It's official: 2012 warmest year on record in U.S.

Last year was the warmest on record in the United States and the second most extreme for droughts, wildfires, hurricanes, and storms, according to a report from the National Oceanic and Atmospheric Administration.

The news continues a dramatic warming trend in the mainland United States: Seven of the top 10 warmest years in the 48 states have occurred in the past 15 years, NOAA said. It comes as the earth continues to heat up from the release of carbon dioxide and other greenhouse gases from power plants, cars and factories.

New England reflected a similar trend: Boston, Hartford, Providence, Burlington, Vt., and other communities experienced record or near-record warming in 2012. Water temperatures off New England are also expected to top the record books once a final analysis is completed.

Scientists say they cannot attribute the warming air –- or water -- temperatures solely to global warming, but they note that global atmospheric and sea temperatures are steadily rising. The news comes as environmentalists begin to push President Obama more aggressively to deal with climate change in his second term.

“Our planet is warming, our oceans are rising, and our storms are strengthening. Congress can no longer afford to watch the devastation from an air conditioned perch,'' said U.S. Rep. Ed Markey in a statement. "We must make 2013 a year for climate action. Waiting around for the next supertorm to flood Boston’s Faneuil Hall or the Boston Garden is not an option.”

To date, 2012 has seen 11 extreme weather disasters that have reached the $1 billion threshold in losses, including Sandy, Isaac, and tornado outbreaks experienced in the Great Plains, Texas and Southeast/Ohio Valley, the report notes.