A new report showing that the contiguous United States had its hottest year ever in 2012 was hailed by a key Senate Democrat as further evidence of the need to address climate change.

The 2012 State of the Climate report released yesterday by the National Oceanic and Atmospheric Administration said last year topped the previous record from 1998 by 1 degree Fahrenheit.

And last year appears to be part of a trend, the report said. It was one of 36 consecutive years that were marked by average temperatures hotter than the 20th century average; the most recent colder-than-average year was 1976. Global averages have climbed an average of 0.28 degrees F per decade since 1970, it said.

Senate Environment and Public Works Chairwoman Barbara Boxer (D-Calif.) cited the report as more proof that "the Earth is warming and the trend is going in the wrong direction."

Global temperature averages have declined the last two years, but James Hansen of NASA's Goddard Institute for Space Studies told reporters on a conference call that fact did not show climate change had stopped.

"On the decadal time scale, it's going to get warmer because we know the planet is out of energy balance," Hansen said.

Summertime anomalies are particularly telling, even when they are smaller, he said, and last year saw summer temperatures in several parts of the United States top average temperatures for the same months by more than 3 degrees F.

"It doesn't sound like a lot, but it has a big impact," said Hansen, who took the morning off from his day job to address climate activists from the faith community at a rally in front of the White House. "I think last year was a good teaching moment, because we can see how big an impact a summer mean anomaly of 2 or 3 degrees can be. It has a huge practical impact."

Last summer was marked by drought, hurricanes and storms that scientists say may have been juiced by man-made climate change.

Boxer has said she plans to devote more of her panel's resources to climate change in the 113th Congress. She is also co-leading a group of senators who plan to introduce legislation on climate change this year and next.

"We cannot afford to ignore these warnings, and must make plans to address this serious threat," she said in a statement. "The health and well-being of our communities and families depends on it."