Poll: More skeptics believe in global warming

WASHINGTON -- A growing majority of Americans think global warming is occurring, that it will become a serious problem and that the U.S. government should do something about it, a new Associated Press-GfK poll finds.

Even most people who say they don't trust scientists on the environment say temperatures are rising.

The poll found four out of every five Americans said climate change will be a serious problem for the United States if nothing is done about it. That's up from 73 percent when the same question was asked in 2009.

And 57 percent of Americans say the government should do a great deal or quite a bit about the problem. That's up from 52 percent in 2009. Only 22 percent of those surveyed think little or nothing should be done, a figure that dropped from 25 percent.

Overall, 78 percent of those surveyed said they believe temperatures are rising, up from 75 percent three years earlier.

The biggest change in the polling is among people who trust scientists only a little or not at all. About one in three of the people surveyed fell into that category.

Within that skeptical group, 61 percent say temperatures have been rising over the past 100 years. That's a substantial increase from 2009, when the poll found that only 47 percent of those with little or no trust in scientists believed the world was getting warmer.

This is an important development because, often in the past, opinion about climate change doesn't move much in core groups -- like those who deny it exists and those who firmly believe it's an alarming problem, said Jon Krosnick, a Stanford University social psychologist and pollster.

Krosnick, who consulted with The Associated Press on the poll questions, said the changes the poll shows aren't in the hard-core "anti-warming" deniers, but in the next group, who had serious doubts.

"They don't believe what the scientists say," Krosnick said. "They believe what the thermometers say."