More Americans than last year believe the world is warming and the change is likely influenced by the Republican presidential debates, a Reuters/Ipsos poll said on Thursday.

The percentage of Americans who believe the Earth has been warming rose to 83 percent from 75 percent last year in the poll conducted Sept 8-12.

Republican presidential candidates, aside from Jon Huntsman, have mostly blasted the idea that emissions from burning fossil fuels and other human actions are warming the planet.

The current front-runner, Texas Governor Rick Perry, has accused scientists of manipulating climate data while Michele Bachmann has said climate change is a hoax.

As Americans watch Republicans debate the issue, they are forced to mull over what they think about global warming, said Jon Krosnick, a political science professor at Stanford University.