Protesters march outside the White House in Washington during a climate change rally on Nov. 29. (Yuri Gripas/AFP/Getty Images)

A clear but declining majority of Americans say climate change is a serious problem facing the United States in a new Washington Post-ABC News poll, with giant partisan disagreement on all aspects of the issue.

The survey finds both support and skepticism for major efforts to reduce climate change on the first day of a Paris summit, with international leaders aiming to forge consensus on measures aimed at slowing the rise of global temperatures.

Sixty-three percent of Americans say climate change is a serious problem facing the country, slipping from 69 percent in June. Just over half say the issue is “very serious,” also dipping by a similar amount.

President Obama will meet with leaders of China and India on Monday in an effort to solidify commitments to cut greenhouse gas emissions. The poll finds that nearly half of Americans, 47 percent, say the federal government should do more to deal with global warming than it does today, marking a decline from 61 percent in 2008 during the final year of George W. Bush’s presidency. About one-third of the public says the government is doing the “right amount,” while nearly 1 in 5 think it should be doing less, a figure that has grown from 1 in 10 eight years ago.

Just over half in the survey, 51 percent, say there is “a lot of disagreement among scientists” over the existence of global warming, down 11 points from 2009 but still higher than the share who say scientists agree with one another on the issue, 43 percent. The widespread sense of scientific controversy contrasts with reviews of climate research and surveys finding that at least 84 percent of scientists agree that the Earth is warming because of human activity.

The large gap between perception and reality of scientific agreement reflects the heated nature of political debates over policy on the issue, as well as the impact of efforts to raise skepticism about scientific consensus. A Yale University study published this month found a tight connection between corporate funding and publications raising doubts about long-term climate change.

Democrats and Republicans continue to have widely different perspectives on the issue. Among Democrats, more than eight in 10 say global warming is a serious problem, 65 percent want the federal government to do more about it and 57 percent believe most scientists agree on whether global warming is happening.

Among Republicans, nearly 6 in 10 say it is not a serious problem, fewer than one-quarter support increased government action and two-thirds think there is “a lot of disagreement” among scientists.

The survey finds that the biggest partisan disagreements exist among those with more education. Among people who have graduated from college, Democrats and Democratic-leaning independents are 43 percentage points more likely than Americans who lean Republican to say scientists agree on global warming. Among those without college degrees, the partisan gap is 22 points, about half as large.

Partisan divisions also are larger among college graduates than others on the seriousness of climate change and whether the government should do more, and may reflect the tendency for better-educated people to align their attitudes more closely with their preferred party.

Beyond partisanship, younger Americans are significantly more concerned about climate change, an issue that is expected to have a much larger impact if temperatures rise consistently over coming decades. More than 6 in 10 of those younger than 30 say climate change is a “very serious” problem, compared with less than half of those older than 50. Younger Americans are more apt to sense scientific agreement on the issue and say the government should do more to combat climate change.

The Post-ABC poll was conducted Nov. 16-19 among a random national sample of 1,004 adults reached on cellular and conventional telephones by live interviewers. The overall margin of sampling error is plus or minus 3.5 percentage points.

Joby Warrick contributed to this report.