The human cause of climate change is an established fact in the scientific community. But some giant corporations such as Exxon Mobil continue to fund NGOs that sow doubt on the subject, with some MEPs tempted by the sceptical line.
"We can be very confident that the net effect of human activity since 1750 has been of warming," a major report by the UN's Intergovernmental Panel on Climate Change (IPCC) said this month, finally confirming what many individual academics have been saying for at least 10 years.
When EU environment ministers met in Brussels on Tuesday (20 February), the fight was over how tough future CO2 cuts should be. No one publicly doubted if CO2 causes global warming - at European government level, the debate has moved on.
But in less formal settings, some European politicians are still willing to revive the old questions. At a recent dinner party in Brussels, three Polish centre-right MEPs, including former Polish prime minister Jerzy Buzek, questioned the IPCC line.
Mr Buzek explained he had seen new studies "which show it's all down to natural cycles" and that Europe had already faced major swings in temperature before the industrial revolution. The MEP is a chemical engineer by background and the parliamentary rapporteur on the EU's â¬7 billion a year scientific research budget.
In January, German centre-right MEP Markus Pieper circulated a note to fellow German group members saying recent hurricanes were part of normal weather patterns and expressing worry that his colleagues were giving too much credence to climate change theory, which he said needs more of an injection of facts.
The European Commission also confirmed that documents seeking to cast doubt on the human causes of climate change are still doing the rounds in Brussels.
"We're getting papers such as this regularly and we look at them," an official in environment commissioner Stavros Dimas' cabinet said. "We have to look at all the scientific material out there, but for the moment we haven't found anything that would change our mind that human action is a factor in climate change."
In a February paper circulated by the Lithuanian Free Market Institute, economist Zilvinas Silenas attacks the IPCC report on the grounds that it uses language such as "likely" or "more likely than not" in presenting its conclusions.
"Too many politicians have staked their reputations on climate change to allow for objective and depoliticised debate," he writes. "Any dissent from this doomsday scenario is labelled bad taste, ignorance or even compared to Holocaust denial."
The Lithuanian Free Market Institute (LFMI) says it is an "independent" think-tank. But a quick glance at its major donors shows that firms such as Mazeikiu Nafta - one of eastern Europe's biggest petrol companies - and cigarette maker Philip Morris stand behind the institute.
The pattern of big energy and tobacco firms helping to fund studies that debunk the recently-established human climate change consensus has been well documented, not least by British writer George Monbiot's book Heat published last September.
The link with tobacco, Mr Monbiot explains, comes after Philip Morris and PR firm APCO in 1993 pioneered a tactic of paying think-tanks and NGOs to debunk the then emerging scientific consensus on the dangers of passive smoking, with the same lobbyists and slogans - such as "junk science" - later cropping up in the climate campaign.
"It is fair to say that the professional denial industry has delayed effective global action on climate change by years, just as it helped to delay action against the tobacco companies," Mr Monbiot's book states.
In January, the US-based Union of Concerned Scientists published a study saying Exxon Mobil has channelled $16 million to 43 advocacy organisations between 1998 and 2005 in order to "manufacture uncertainty about the human causes of global warming."
The network of Exxon-funded climate change sceptics include major NGOs such as the Cato Institute and the Heritage Foundation, as well as grass roots or academic-sounding organs such as The Centre for the Study of Carbon Dioxide and Global Change.
"I think the science world has done its very best to document global warming and communicate the issue, but we are up against financially far more powerful interest groups using professional PR tactics," Stefan Rahmstorf, ocean physicist at the Potsdam Institute for Climate Impact Research, told EUobserver.