According to the CNN-ORC poll, 49 percent said global warming has been scientifically proven to be the result of man-made emissions. That’s a strong plurality, but down from 56 percent in 2007.

In addition, 25 percent deny that global warming exists at all, and 24 percent say the climate is changing but not because of man-made emissions.

The responses largely split along partisan lines, with 66 percent of Democrats saying global warming is man-made, 48 percent of independent voters saying the same, and 28 percent of Republicans agreeing.

In 2009, the House passed an Obama-backed climate change bill, but cap-and-trade legislation failed to move in the Senate.

On Monday, Obama returned to the issue in his inaugural address, saying “we will respond to the threat of climate change" because failure to act "would betray our children and future generations.

"Some may still deny the overwhelming judgment of science, but none can avoid the devastating impact of raging fires and crippling drought and more powerful storms,” said the president.

The CNN-ORC poll of 814 adults was conducted on Jan. 14 and Jan. 15 and has a 3.5 percentage point margin of error.