|Arctic melt has pushed the Jet Stream into a more |
meandering, S-shape pattern, dragging down and
stalling cold and wet conditions over Europe
A wet summer and autumn, followed by a cold winter and spring, in the UK and Ireland have hit wheat and potato production and cattle feed, a foretaste of how climate change can affect food security, even in the developed economies.
And the culprit in this drama is rapid Arctic melting, which has destabilised the Jet Steam and brought extreme weather – unusual cold, heavy snowfall, record rain and hot spells — to much of northern Europe and North America, and record heat to the Arctic. Following Superstorm Sandy’s battering of the US north-east coast in 2012, flooding in June across central Europe was the worst in 400 years.
Rapid Arctic melting – sea-ice volume in September 2012 was down by four-fifths compared to the summer average 30 years ago – has help change the Jet Stream, the river of high altitude air that works to separates Arctic weather from that of northern Europe, Russia and Canada, and which governs much northern hemisphere weather.
The ice loss has added to ocean and atmospheric heat, pushing the Jet Stream into a more meandering, S-shape pattern, dragging down and stalling cold and wet conditions over Europe, and bringing record heat to the Arctic, as was dramatically experienced in Alaska last month.
Professor Jennifer Francis, of Rutgers Institute of Coastal and Marine Science, says the Arctic-driven changes to the Jet Stream allows “the cold air from the Arctic to plunge much further south. The pattern can be slow to change because the [southern] wave of the jet stream is getting bigger… so whatever weather you have now is going to stick around”.
In March, new research found that “the severe loss of summertime Arctic sea ice — attributed to greenhouse warming — appears to enhance Northern Hemisphere jet stream meandering, intensify Arctic air mass invasions toward middle latitudes, and increase the frequency of atmospheric blocking events like the one that steered Hurricane Sandy west into the densely populated New York City area”.
And a recent study by Liu et al found that “the recent decline of Arctic sea ice has played a critical role in the recent cold and snowy winters” across the northern hemisphere.
Last September, Francis warned that 2012′s record sea ice melt could lead to a cold winter in the UK and northern Europe. And so it turned out, with farmers copping the consequences:
WET SUMMER AND AUTUMN: Six out of the last seven summers in the UK (since the record-smashing Arctic melt of 2007) have seen below-average temperatures and sunshine, and above-average rainfall. 2012 was the UK’s second wettest year on record, with autumn rain almost 50% higher than long-term average. In Ireland, twice the average amount of rainfall was recorded in many parts of the country during the three summer months of 2012. People across the UK and Ireland will readily tell you that “We haven’t had a summer in four or five years”, and unusually, for them, complain of “bitter” and “terrible” winters, with temperatures dropping as low as –18C in Northern Ireland.
COLD WINTER AND SPRING: “It’s been the longest winter on record in this country. Not since the records began 70 years ago has there been a March as cold as this year’s. It’s been followed by the coldest April in 25 years in some areas of the country,” reported the Irish Examiner on 9 May 2013. The Irish spring in 2103 was coldest in 62 years across most of country, and dull and windy. Spring in the UK this year was the coldest in 50 years.
BAD COMBINATION: This combination of events has wrecked farmer’s schedules. Less growth in a dull 2012 summer – combined with water-logged crops and pastures in autumn – reduced yields, and some crops had to be left in the ground. The spring 2013 growing season, including for apples and pears as well as pasture, started up to six weeks late due to the cold, dull conditions. And waterlogged fields meant that across Ireland cattle were still being kept in their winter sheds in the first week of June, ostensibly a summer month. The consequences – whilst mild compared to climate-change impacts on vulnerable communities in the developing world from the African Sahel to Asia’s changing monsoons – show how easily the security of food production can be disrupted:
WHEAT: In the UK, a wet autumn, hard winter and cold spring has resulted in one of the smallest wheat harvests in a generation, 30% below normal. Britain, generality the third biggest wheat grower in the EU, will be a net importer for the first time in 11 years. Charlotte Garbutt, a senior analyst at the industry-financed Agriculture and Horticulture Development Board says: “Normally we export around 2.5m tonnes of wheat but this year we expect to have to import 2.5m tonnes.” The latest analysis from the UK Department for the Environment, Food and Rural Affairs says total farming income decreased by £737million in 2012 to £4.7bn, as farmers faced both crop losses and higher feed costs.
STOCK LOSSES: Late snowstorms across England, Sotland, Wales and Ireland March 2013, with drifts of up to 5 metres, killed an estimated 40,000 newborn lambs. In ireland’s west, one-quarter more animals died in the first three months of 2013 compared to 2012, with some vets trained to look for suicidal behaviour in farmers.
POTATO SHORTAGE: A wet autumn and poor season in 2012 prevented many crops being harvested in Ireland. Supermarket price-squeezing has also driven some farmers out of the industry, together resulting in reduced yields of at least 30 per cent in 2012. By spring 2013, potato prices had almost tripled in many parts of Ireland, with supplies exhausted and a reliance on imports from central Europe.
Limavady farmer, James Wray, told UTV News that said the changing weather in recent weeks had forced the price up: “This year has been a terrible growing season with loads of crops lost and loads of crops not harvested and any crops that have been harvested have produced low yields. There just isn’t any potatoes left in the country, there are no farmers with potatoes left, so whatever potatoes are about, are very, very expensive. If you go to any of the major supermarkets most of their potatoes are coming in from Europe just to bridge the gap.”
Potato shortages have a particular cultural resonance in Ireland as a consequence of the Irish potato famine of the mid-nineteenth century, which killed a million people and forced another million to emigrate.
FEED SHORTAGE: In the last week of May (the final week of spring), farmers in Ireland’s west were queuing for hay and silage imports from England, France and Netherland as their winter feed became exhausted and a lack of pasture growth in spring due to cold and overcast conditions, and wet fields, prevented cattle from being moved from their winter sheds. More than 13000 tonnes of feed was imported, but even so farmer Enda Stenson said local farmers “have neither money nor fodder”. Many had sold down their herds to be able to buy feed for the remainder.
BEES IN TROUBLE: Bad weather and disease is also threatening honey production, with some beekeepers expecting to produce no honey as bees have been unable to mate and hives are decimated. And bees play a crucial role in pollinating many crops.
Jim Donohoe, of the Federation of Irish Beekeepers’ Associations, told the Irish Independent that the problem was weather related: “We’ve had bad summers before, but because of the wind, rain and lack of sunshine, we’ve had serious problems with colonies wanting to swarm, but the queens being unable to mate with drones which refused to fly because there wasn’t calm conditions. This year, we had a delayed winter where bees couldn’t fly. The flowers were delayed coming out, and that crucial period meant bees died from old age. All of this combines to about 50pc of colonies being lost. If we don’t get milder weather, the losses will be closer to 75pc.
These stories may seem trivial compared to the devastating impact of climate change on global food security and prices, and their political consequences. Writing on Egypt’s new political turmoil, Nafeez Ahmed notes that:
“Food price hikes have coincided with devastating climate change impacts in the form of extreme weather in key food-basket regions. Since 2010, we have seen droughts and heat-waves in the US, Russia, and China, leading to a dramatic fall in wheat yields, on which Egypt is heavily dependent. The subsequent doubling of global wheat prices – from $157/metric tonne in June 2010 to $326/metric tonne in February 2011 – directly affected millions of Egyptians, who already spend about 40% of their income on food. That helped trigger the events that led to the fall of Hosni Mubarak in 2011, but the same configuration of factors is worsening.”
And Lester Brown, head of the Earth Policy Institute in Washington, has warned that grain harvests are already shrinking as US, India and China come close to ‘peak water’. He says that 18 countries, together containing half the world’s people, are now over-pumping their underground water tables to the point – known as “peak water” – where they are not replenishing and where harvests are getting smaller each year.
Together these stories paint a compelling picture of the threat to food security from climate change, not just in the Middle East, Asia and Africa, but in the heart of the developed world too.
David co-authored the book Climate Code Red (2008).
David frequently posts at the Climate Code Red website.
Above article was first posted at Reneweconomy.com.au
- Polar jet stream appears hugely deformed - by Sam Carana, December 20, 2012