Melting ice in the Arctic still a major problem
THE EUROPEAN Environment Agency (EEA) has published a report describing the summer of 2012 in the Arctic. On the face of it the publication of that report would seem to have little or nothing to do with us here in Ireland but it does impact on us in that changing climate in the Arctic is one of several factors causing sea level to rise here.
The problem in the Arctic is fourfold. First, due to global warming ice is melting at a faster rate than many experts had predicted. Year on year the limit of summer sea ice has got less and less since records began in 1979. The extent of the sea ice fell from a September average of 6.5 million kilometres squared over the last three decades to a record low of less than 4 million kilometres squared in September 2012. Furthermore, the remaining ice is thinner and is therefore more likely to melt faster.
The second problem is that summer snowfall is declining. In the past the great expanse of whiteness from snow and ice in the Arctic acted as a reflector bouncing the heat of the Sun back into space. Nowadays the increasing extent of darker areas acts as a heat absorber soaking in the Sun's energy thereby warming the planet resulting in more ice melting that in turn causes sea level to rise.
The third problem is that permafrost is melting at an accelerated rate. Permafrost is frozen soil. In the past the permafrost acted as a sink for carbon dioxide and methane gases. Nowadays the permafrost is releasing these gases as it thaws. Increased greenhouse gasses in the atmosphere traps heat thereby warming the planet, resulting in more ice melting and so on.
And the fourth and final problem is that the huge Greenlandic ice sheet is losing ice mass at an alarming rate. It has been estimated that if the Greenland ice sheet was to melt in its entirety global sea level would rise by as much as a frightening seven metres.
At present sea level is rising at the rate of about 3mm per year with very high levels of uncertainty about how that might accelerate. What is likely to happen in the Arctic before the end of this century and how it will impact on the four million people who live there is largely unknown. How wildlife will cope and how climate will be affected is also largely unknown.
Changing climate in the Arctic is one of several factors causing sea level to rise here.