WASHINGTON - According to the Pew Research Center for the People and the Press, Americans are cooling on the topic of global warming.
Last week's poll results indicate what one pollster says is growing "green fatigue".
Falling 20 points in three years, according to Pew, just 57 percent of Americans now believe there is solid evidence for global warming.
The number of Americans believe that human-induced pollution is to blame for climate change is also falling.
The Pew poll included 1,500 adults with varying backgrounds.
The new poll shows that the number of people claiming that the planet Earth has warmed in recent decades is down-from 77 percent in 2006 to 71 percent in April 2008.
Some experts are blaming the poll results on the bad economy and on Americans' change of focus, but others point to the "green fatigue" factor.
"Americans are appear to be getting bored with the endless talk of climate change and with corporate and political green messaging," said non-partisan D.C. polster Thom Eisner.
"I call this phenomenon green fatigue. Businesses have been patting themselves on the back about how wonderful they are for being 'green' and politcial messages of climate doom-and-gloom simply aren't resonating with average Americans. Add to that these facts the mainstream scientists who have remained silent on the subject and the new Pew results aren't surprising to me," Eisner said.