WASHINGTON - A new national survey released Monday finds that 7 percent of likely US voters remain undecided about whom they will vote for President. However, the majority of these undecided voters say presidential candidates' positions on global warming will be one of several important factors determining how they cast their votes in November.

The survey found that undecideds are much more similar to likely Obama voters than likely Romney voters across a range of climate change and energy-related beliefs, attitudes and policy preferences.

The survey found that 80 percent of undecided voters believe that global warming is happening, while only three percent believe it is not. By contrast only 45 percent of likely Romney voters believe global warming is happening. Two out of three undecideds (65 percent) say that if global warming is happening, it is mostly human caused, the same as likely Obama voters (65 percent). Only 27 percent of likely Romney voters, however, say that if it is happening, global warming is mostly human caused, while fully half say global warming is caused by natural changes in the environment.

Undecided voters and likely Obama voters say that President Obama (64 percent and 61 percent, respectively) and Congress (72 percent and 78 percent) should be "doing more" about global warming.

By contrast, fewer than half of likely Romney voters think the President or Congress should be doing more (35 percent and 35 percent, respectively) and, in fact, these voters are more inclined to say they should be doing less to address global warming (47 percent and 44 percent).

"Undecided voters lean towards pro-climate action and will be considering the candidates' positions on global warming when they vote in November," said Anthony Leiserowitz of Yale University. " The fact that undecideds look remarkably similar to Obama voters on climate change could prove important on election day."

The data are based on a nationally representative survey of 1,061 American adults conducted from Aug 31 to Sept 12, conducted by the Yale Project on Climate Change Communication and the George Mason University Center for Climate Change Communication.