Cold comfort from the weather gurus: it's the new normal
Published 31/03/2013 | 05:00
Thousands of sheep and lambs froze to death this week and spring daffodils peeked above snow gathered by children to sculpt Easter bunnies, all just days after torrential rain flooded parts of the country.
For some experts, this weather is not merely a sign that winter has outstayed its welcome but a warning that climate change has begun to take its toll.
This month will likely end as the coldest March in 50 years in the east and north-east and the chilliest in 30 years in the west of Ireland, Met Éireann records indicate. Temperatures are at least half the average for March 2012, when the mercury soared to as high as 22C in Co Mayo.
The nation is preparing to switch clocks forward by an hour tomorrow morning, heralding the arrival of official summer time. The weather is not playing along, but, according to Kieran Hickey, a climate-change expert who lectures in geography at NUI Galway, this is a pattern Ireland may have to become accustomed to.
Hickey, author of Deluge: Ireland's Weather Disasters 2009-2010, believes climate change has already started to make turbulent weather events more commonplace.
"If you look at the records since the first recent weather disaster in November 2009, there has been a significant event every six months, such as flooding in Cork," he said.
"We are getting lots of extremes and there has been no let-up since 2009, which means the climate is swinging. The IPCC (Intergovernmental Panel on Climate Change) predicted climate change would lead to a lot of extreme weather and less predictability of what were once normal weather expectations. That is what's happening.
"You're always going to get cold spells as part of a climate's natural cycle but we've had three cold spells since 2009 and three or four major flooding events. That's a sign climate change has come into effect."
Met Éireann has attributed the prolonged wintry conditions to a stubborn weather pattern across Europe that has often been in a blocked state over recent months.
High pressure from Scandinavia and Greenland has been preventing low pressure from the Atlantic from taking its usual path to the north of Ireland and the UK and bringing the country mild and wet weather. Instead, low-pressure systems have been diverted further south, allowing cold easterly winds to prevail. The jet stream, the meandering high-altitude river of air that typically steers milder weather towards Ireland, has stubbornly refused to budge from its southerly position.
"We have to ask ourselves why the jet stream is stuck," Hickey said. "Normally, we would expect the boundary between the polar air coming from the north and the warmer Atlantic air to be north of us this time of year. But it's not behaving as it should be."
A growing number of scientists believe the position of the jet stream has been altered by the loss of ice from the Arctic. Jennifer Francis, a research professor with the Rutgers Institute of Coastal and Marine Science, last week said melting ice from the Arctic is adding heat to the ocean and atmosphere, shifting the position of the jet stream.
The extent and volume of sea ice in the Arctic ocean fell to a record low last autumn, and satellite records published this month by the National Snow and Ice Data Centre in Boulder, Colorado, found that the ice extent is near the lowest ever recorded for this time of year.
John Sweeney, a climatologist at NUI Maynooth, believes the world is at a "climate cliff face" and has about eight years to tackle climate change before freak weather events become more frequent. Sweeney is a member of the IPCC, which was jointly awarded the Nobel Peace Prize in 2007 with former US vice-president Al Gore.
However, seemingly unseasonal snowfalls are not entirely rare in Ireland. As Kevin Kearns wrote in his 2011 book Ireland's Arctic Siege – The Big Freeze of 1947, temperatures between mid-January and mid-March that year were, at times, lower in Ireland than in Antarctica. The country experienced snowdrifts of between 12ft and 20ft and five major blizzards.
About 600 people died directly from the cold, with many more dying from the flu. The snow was so deep that people used telephone wires to guide them as they walked, and the Liffey and other rivers were completely frozen. Unlike the recent winter freezes of 2009 and 2010, conditions in the spring of 1947 were exacerbated by a shortage of fuel and post-war food rationing.
Even in the last decade, snow has not been confined to winter. In 2010, temperatures plunged to as low as -7.6C on March 11. During the first half of March 2009, schools closed in Munster and Connacht due to a blanket of snow.
For climate sceptics, historic records of bizarrely late snowfall suggest Ireland's springtime winter wonderland amounts to little more than natural variations in climate. For climatologists such as Hickey, man-made climate change has turned weird weather into the new normal.