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 4 out of every 5 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 U.S. 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. In general, U.S. belief in global warming, according to AP-GfK and other polls, has fluctuated over the years but has stayed between about 70 and 85 percent.