Citizen scientists can help to solve a critical question raised by England's wettest winter in at least 250 years: was climate change to blame?

Spare home computer time lent to researchers at the University of Oxford will allow an intensive modelling effort to determine whether global warming made the deluge more likely.

The role of climate change in the downpours, that resulted in at least £1bn of flood damage, has been fiercely debated. The prime minister, David Cameron, told parliament he "very much suspected" a link between global warming and climate change, while the statement from the Met Office's chief scientist that "all the evidence suggests a link to climate change" was attacked by leading climate sceptic Lord Nigel Lawson as "absurd".

The result of the study should be ready within a month and follows earlier research which found that heavy flooding in England in 2000 was made two to three times more likely by climate change.

Professor Myles Allen, who leads the weather@home research, said basic physics shows that warm air holds more water and rainfall gets more intense, but added that the chaotic nature of weather means that no specific flood can be attributed to human-induced climate change alone.

"We can, however, ask and answer the question of how the odds of getting an extremely wet winter have changed due to man-made climate change: have past greenhouse gas emissions loaded the weather dice?" Allen told the Guardian. "We need to find out if we are getting "too many double-sixes" with the British weather dice."

He said the team did not know what the result would be and would be discovering the answer at the same time as the public. "It is absolutely possible the experiment will tell us climate change had nothing to do with the extremely wet winter."

The project will see the winter weather of 2013-14 rerun about 30,000 times in computer climate models. One set of models will start with the actual climate conditions at the start of December 2013, while another set will begin with conditions that would have existed in a world without climate change, ie much lower greenhouse gas levels, lower sea surface temperatures and much greater sea ice cover in the Arctic. Comparing how often an extremely wet winter occurs in each set of models will show whether or not global warming loaded the weather dice.

The record wet winter is by definition an extreme event and therefore, to ensure the result is statistically convincing, the models have to be run many thousands of times and therefore require huge computing power. "That is why we are asking for the help of the general public," said Allen. "We will be able to go from speculating about the influence of climate change to providing scientific evidence. The climate is changing, and the sooner we understand in detail what these changes mean for Britain, the better."

Previous research by Allen's team revealed the strong influence of climate change as far back as 2000. A study published in 2011 concluded that serious floods in southern England in 2000 would have been between one-third and one-half as likely in the absence of man-made greenhouse gas emissions. But Allen noted that global warming could be beneficial in some circumstances: the risk of flooding due to the rapid melting of spring snow, which drove widespread flooding in 1947, could be less likely now, he said.

Other so-called "attribution" studies have also linked heatwaves to climate change. The great heatwave that struck Europe in 2003 and led to more than 30,000 deaths was made at least twice as likely by climate change, while the chance of the extreme heat that struck eastern Europe in 2010, killing 50,000 people and destroying the wheat harvest, was tripled by global warming.

The record wet winter in England has prompted a renewed debate on the influence of climate change on extreme weather, which scientists have warned will be intensified in a warmer world.

Climate economist Lord Nicholas Stern said it was "a clear sign that we are already experiencing the impacts of climate change" while Labour leader, Ed Miliband, warned that the UK was "sleepwalking into a national security crisis on climate change". But the environment secretary, Owen Paterson, widely regarded as a climate sceptic, refused to echo Cameron's warning of a link when asked to do so in the House of Commons in January.

• See videos and graphs about the weather@home project here.

