The shape of British summers to come?

Seeing satellite pictures from Greenland last month, scientists from Nasa at first couldn't believe what the data was telling them. About 97% of the Greenland ice sheet was melting. The rate was unprecedented, with the thaw more widespread than ever as unseasonally warm weather across the Arctic took effect.

"It was so extraordinary that at first I questioned the result: was this real or was it due to a data error?" wondered Son Nghiem, one of the scientists responsible for the research at Nasa's Jet Propulsion Laboratory in Pasadena. In a normal summer, some melting is observed over about half the island's surface area. This new data – from three satellites – raised serious concerns over the progress of global warming and the likely consequences.

For scientists at the Met Office's world-renowned Hadley research centre in Exeter, the question was not just how fast Greenland was melting, but something much trickier. They have been crunching through years of data from dozens of satellites, trying to establish whether the conditions in the Arctic circle are related to the record-breaking washout of a summer in the UK.

The news could be disconcerting for fans of the British summer. Because when it comes to global warming, we can forget the jolly predictions of Jeremy Clarkson and his ilk of a Mediterranean climate in which we lounge among the olive groves of Yorkshire sipping a fine Scottish champagne. The truth is likely to be much duller, and much nastier – and we have already had a taste of it. "We will see lots more floods, droughts, such as we've had this year in the UK," says Peter Stott, leader of the climate change monitoring and attribution team at the Met Office. "Climate change is not a nice slow progression where the global climate warms by a few degrees. It means a much greater variability, far more extremes of weather."

A series of unusually wet and cold summers has afflicted the UK for several years. Remember the devastating floods of 2007, when some areas received double their normal rainfall for June? Or the predictions of a "barbecue summer" in 2009 that backfired badly on the Met Office as the (correctly anticipated) high temperatures were accompanied by heavy clouds and rainstorms? The impression that many Britons have had that summer weather has been getting worse in recent years is borne out by the data – five out of the last six years (2007-2012), have shown below-average sunshine from June to August, and in some cases well below average. All have had above-average rainfall – in some cases more than 50% above the long-term average. "It is not just a perception – we have had a run of relatively poor summers," says Stott.

This year has been the worst so far. April was the wettest on record, and so was the period from April to June. The sun was missing too – June was the second dullest recorded. Hopes that August might bring more settled weather were dashed when the first few days brought floods as far apart as Scotland and Somerset, forcing scores of people from their homes. The unseasonally wet and miserable summer may have failed to dampen the Olympic spirit but it has brought misery to thousands.

Nor has the UK been alone in suffering extreme weather. In the US, the eastern seaboard has been hit by heatwaves and storms but even worse has been the "dustbowl effect" in Texas and across much of the nation's agricultural heartland. India's monsoon failed to appear on schedule, leaving millions of farmers in the subcontinent facing destitution. Floods in Beijing, after the heaviest rainfall in 60 years, caused devastation to millions.

The consequences across the world have been and will be dire. A food crisis is now all but inevitable, according to the US agriculture secretary. Emergency plans are being discussed in India, while in China the clear-up is accompanied by concerns that environmental degradation may be making the country's problems worse.

Attributing any single weather event, or short pattern of events, however extreme, to climate change is always tricky. Extreme weather events occur, in the scientists' term, stochastically – they happen by themselves, unpredictably, owing to the natural variations of the weather.

But the science of climate change has progressed rapidly in recent years. Last month, the Met Office and NOAA, the US National Oceanic and Atmospheric Administration, published a groundbreaking report that showed recent events could be attributed to human causes. Last year's unseasonally warm November in the UK – the second hottest since records began in 1659 – was shown to be at least 60 times more likely to have happened because of climate change than because of natural variations in the earth's weather systems.

Stott says: "We are much more confident about attributing [weather effects] to climate change. This is all adding up to a stronger picture of human influence on the climate."

For the British Isles, the melting Arctic could hold the key to whether the weather is changing under human impacts. Recent poor summers have been strongly linked by scientists to a change in the usual position of the jet stream, a weather system that normally lies in high latitudes during the northern hemisphere summer.

Earlier this year, two US scientists published a paper in the journal Geophysical Research Letters, suggesting that the meandering of the jet stream could be linked to the reduction in sea ice. Edward Hanna, reader in climate science at the University of Sheffield, who is taking part in similar research, explains: "The last six summers since 2007, while often rather cool and wet over the UK, have brought Greenland unusually high air pressure, mild southerly winds, record-breaking temperatures and melting of the land ice." The link, he believes, is that Arctic sea-ice losses and the release of heat over the Arctic Ocean have tended to weaken the jet stream and make it more meandering. This has brought more low pressures over Britain, less stable conditions, more cloud cover and rain-bearing weather systems from the Atlantic.

This year, the jet stream moved much more than usual, passing south of the UK. It also persisted in this position for an unusually long time. If this pushing of the jet stream southward is indeed linked to less sea ice over the Arctic circle, as Hanna suspects, then the signs are that we will see many more of these wet summers in future.

Despite the recent advances in climate-change science, it is too early to say whether this is certain. Hanna warns: "Six years is a relatively short time, and there are quite a number of other factors – sea-surface temperatures, variations in the sun's power and the partly random and chaotic nature of atmospheric circulation – that can affect jet stream patterns, so further research is needed to make us more confident about the nature of these changes."

That means it could take several years – aided by the roomfuls of supercomputers at the Met Office – to come up with more sturdy evidence linking our poor summers with climate change. If the link is established, it could signal similarly dull and disappointing British summers for many years to come.

But one piece of the picture may be about to fade. The majority of the most valuable data we have amassed – including the images of Greenland's surface melting – comes from between 20 and 30 satellites that are now under threat. Ageing satellites are being removed from orbit and not replaced, while those that remain are at ever greater risk of buffeting from the debris that now litters space. "There is a severe danger of not being able to see so clearly [from space] in future with the fall-out of satellites, uncertain government funding and so on," says Kate Willett of the Hadley Centre.

Unless the satellite data continues to stream down, we will never know whether the UK is at risk of a new age of drizzly summers and dry winters, and drought alternating with flooding.

Meanwhile in Greenland, inhabitants have been basking in an almost unheard-of heat, regularly topping 20C, with a succession of dry sunny days dominating the weather over the past two months. "It's been lovely here, much warmer than usual – we've really been enjoying a nice summer," says Henrik Stendal from his offices in Nuuk, the capital. British staycationers can only shiver in envy.