A new opinion poll has revealed that nearly one in two voters think that there is no evidence of humans causing global warming.
The ICM survey for The Sunday Telegraph will dismay proponents of "man-made" climate change - including leading scientists and the majority of world governments - as they gather in Copenhagen for the landmark climate summit.
Asked if they backed the main conclusion of the Intergovernmental Panel on Climate Change (IPCC), that humans are largely responsible for modern day rises in temperatures, 52 per cent of voters agreed.
However, 39 per cent said climate change had not yet been proven to be man made, while seven per cent simply denied the phenomenon was happening at all. Furthermore, fewer than one in four voters (23 per cent) believed that climate change was "the most serious problem faced by man" - a view endorsed by governments across the world.
A clear majority (58 per cent) said it was merely "one of a number of serious problems" while 17 per cent believed it has been exaggerated and is "not a very serious problem."
The survey follows the recent raising of tensions between proponents of man-made climate change, which is the prevailing scientific view, and those who take a more sceptical stance.
Gordon Brown, who will attend the two-week, 192-nation Copenhagen summit, denounced "the behind-the-times, anti-science, flat-earth climate sceptics" who challenged the prevailing view.
Lord Stern, the British government's leading adviser, has warned that 10 billion tonnes of greenhouse gas emissions must be taken out of the atmosphere by 2020.
So far agreement is in place for only half of that amount - but chances of a landmark deal at Copenhagen, where President Barack Obama will also attend, appear slim.