Concern and awareness for climate change and the environment peaked in 2007 at the time of the Live Earth concerts and the launch of Al Gore’s documentary "An Inconvenient Truth", according to a survey by The Nielsen Company and the Oxford University Institute of Climate Change.

The survey – conducted among 27,548 consumers in 54 countries – shows that in 2007 41 percent said they were very concerned about climate change. In October 2009 the number had declined to 37 percent.

"The global recession and economic woes temporarily knocked the climate change issue off the top line agenda, but as the recession is now beginning to recede, we expect the Copenhagen Summit may push this important issue to the forefront again," said Jonathan Banks, Business Insights Director Europe, The Nielsen Company.

The highest levels of concern were expressed in Latin America (57 percent) and Asia Pacific (42 percent). In the US the number of very concerned declined from 34 percent in 2007 to 25 percent in October this year.

Another poll by GlobeScan goes in the opposite direction, according to BBC News. This poll shows that nearly two thirds of 24,071 people polled in 23 countries said climate change was a "very serious" problem – up from 44 in 1998.