The dramatic loss of summer sea ice in the Arctic has prompted a lot of research interest in the way that this is affecting weather patterns around the northern hemisphere. The latest contribution is Influence of Arctic sea ice on European summer precipitation, by Dr James Screen of the University of Exeter [PhysOrg]. In this “video abstract”, he explains how reductions in Arctic sea ice affect the position of jetstream — the ribbon of winds winding around the planet that guides weather systems — bringing more summer storms to Western Europe, and a recent run of record-setting wet summers to the UK. But as he points out, the effects are planet-wide:
The impacts are not just over northwest Europe. Actually in the model, what we find is that whilst the sea ice loss increases rainfall over northwest Europe, we actually find drier conditions over Mediterranean Europe. Also the jet steam shifts over North America, which can have implications for the weather there too.
Dr Screen’s study underlines a point that I have been making for some time: rapid climate change is not something theoretical that will happen in the future — it’s happening now and we’re feeling the effects. Warming in the Arctic is driving sea ice loss, and the atmospheric consequences are changing the shape of the weather right round the northern half of the planet.
It’s worth noting that an especially vigorous jetstream directed and helped to intensify the recent huge European storm that hammered the UK, Germany and Denmark, killing 16 people and causing huge amounts of damage. Christopher Burt at WeatherUnderground provides a handy overview of the storm that has four names — St Jude, Christian, Simone and Carmen. The storm centre moved 2,000 km in 26 hours, a remarkable pace of 77 kph.
Over the last few years I’ve made more than a few references to the emerging relationship between warming in the Arctic and the loss of sea ice to changes in the patterns of Northern Hemisphere weather. Take a look at this map, plotted at NOAA’s ESRL site using NCEP/NCAR reanalysis data (click on the image to see the original plot):
Mr Morrison invites us all to come on home, and have a Celtic new year — which is always a good thing, as I can testify, being a Celt of many generations standing. While I wait for the ham to subside and the cabernet merlot to wash out of the system1, I’ll point you to the thoughts of George Monbiot, who is less than impressed with the old year:
It was the year of living dangerously. In 2012 governments turned their backs on the living planet, demonstrating that no chronic problem, however grave, will take priority over an immediate concern, however trivial. I believe there has been no worse year for the natural world in the past half-century.
Nor do the efforts of the British government bring him much cheer:
Last week the UK Meteorological Office issued its annual forecast for the global average temperature for the year ahead. They’re expecting a warm year, but very few people seemed to notice just how hot. Here’s what the press release had to say:
2013 is expected to be between 0.43 °C and 0.71 °C warmer than the long-term (1961-1990) global average of 14.0 °C, with a best estimate of around 0.57 °C, according to the Met Office annual global temperature forecast.
Taking into account the range of uncertainty in the forecast and observations, it is very likely that 2013 will be one of the warmest ten years in the record which goes back to 1850, and it is likely to be warmer than 2012.
Most press coverage ran with the “one of the warmest years” line, a simple elaboration of the press release, but few noticed that the Met Office were actually predicting a new global temperature record — perhaps because the Met Office wasn’t exactly trumpeting the fact from the rooftops. Admirable caution, you might say.
Extreme weather events are where the climate change rubber hits the road, and if events over the last month are anything to go by, global warming is currently doing doughnuts and burnouts on tarmac right round the globe. Kevin Trenberth put it rather nicely in an interview with PBS Newshour in the US: “This is a view of the future, so watch out.” John Vidal in The Guardiansums up the situation rather well:
…how much more extreme weather does it take for governments and individuals to act, or for the oil companies to withdraw from the Arctic, or the media to link global warming with the events now being witnessed around the world? Must the sea boil, the Seine run dry, New York flood and the London Olympics be consumed by fire before countries are shocked into taking concerted action?