This was an off-the-cuff quip by a friend of mine last week as we waited to pick up our children from play school. And my God it has been cold! Temperatures are well below normal for this time of year. I am still wearing my hat and gloves for Christ sakes. But then this is Ireland, and the weather always gives us something to talk about.
One of the reasons why it might be so cold this spring, ties in with a large body of cold water that has formed near Greenland. This cold blob of water could be effecting to our weather here on the Emerald Isle, driving increased storms over the winter and pushing the current chilly temperatures this spring.
Imagine if Usain Bolt broke the 100 m sprint record at every one of his last 11 races. Everyone would be talking about it! Well climate records have been crashing month after month for the last year. This is big climate news, but few people are talking about it. March 2016 marked the 11th consecutive month that the monthly global temperature record has been broken. You may also have heard that 2015 was the hottest year on record globally. It smashed 2014, the last record year, by a staggering .2°C and 2016 is set to beat both 2015 and 2014 for the global heat record. In fact 15 of the 16 warmest years on record have occurred in the 21st century.
But there has been one strange anomaly to all this. Out in the Atlantic something quite different has been happening. A large expanse of cold water, roughly the size of the European Union has started to form. Stretching all the way from Greenland to the West Coast of Ireland, it is one of the only parts of the world that is not warming. In fact it has cooled but this cooling is also breaking records. It is being called the Atlantic cold blob and recently it has starting to concern some of the world's leading climate scientists and for very important reasons.
A Soft Day Thank God!
The Atlantic Meridional Overturning Circulation (AMOC), known as the Gulf Stream here, is hugely important to Ireland's mild climate. Ireland lies on a similar line of latitude to Calgary in Canada, regular host to the Winter Olympics but nowhere near as cold as Calgary! The AMOC plays a major role in our soft Irish weather but also is a key player in the worlds climate system. The AMOC brings warm tropical water northward from the Caribbean, helping to warm Europe and sends cold salty water back down to the tropics driving huge ocean currents all around the planet.
Now research by two leading climate scientist Stefan Rahmstorf and Michael Mann concludes that the AMOC circulation has shown exceptional signs of slowdown over the last century, and that melting ice from Greenland is to a large degree contributing to this slow down. Global climate models have long predicted this slowdown of the AMOC with a 12% to 54% decline in the circulation strenght forecast by 2100.
However the Rahmstorf/Mann research is suggesting that these models could be underestimating the rate of slowdown. The worrying conclusion from their research is that none of the climate models predicted a slowing down of the AMOC as early as current observations are presenting. Giving rise to concerns about rapid climate change.
Abrupt climate change
The idea of abrupt climate change is not new. Recent research suggests that several elements of the climate system could be tipped into a different state by global warming, causing irreversible economic damage as well as significant localised climate impacts around Europe.Such rapid climate change has happened in the past. One such rapid cooling event happened around 12,900 years ago. Towards the end of the last ice age. This is a well studied event called the Younger Dryas (YD) and it caused a rapid change in Europe's climate. Greenland ice core records suggest that the onset of the YD could have happened very quickly, possibly in as little as 3 years. Scientists think that principle cause for the YD cooling was a partial reduction in the AMOC caused by an increase in freshwater runoff from ice sheets in North America.
Climate change now
Recent studies are now showing that huge volumes of fresh water is flowing from rapidly melting ice in Greenland. This fresh water may be having a significant contribution to the current slowdown of the AMOC by helping to dilute ocean waters in the subpolar Atlantic. Scientists also think that this freshwater flowing into the Atlantic can be directly linked to man-made climate change.The Gulf Stream is slowing down faster than it has ever done in the past 1000 years.
Initial indications suggest that as a result we may experience cooler and dryer summers. We could also see a strengthening of winter storms arising from an increased temperature difference between the sea surface and the atmosphere. All this could give raise to issues of water availability and crop production here.
While not The Day After Tomorrow which was based on a full AMOC shutdown and with non scientific, catastrophic Hollywood consequences. This new research is important for all of us. It should stimulate an urgent discussion and research on how this large area of cold water might influence Irelands weather and future climate.