Saturday, 22 January 2011
The death of Greenland's canary in the 'Climate Change Coal Mine'?
Without the ‘Greenhouse Effect’ life would not exist on earth. The Earth’s atmosphere lets in just enough ultraviolet and visible light, but traps some of the infrared radiation and heat and works just like a greenhouse; light enters and heats up the inside and the glass traps some of it in. This is a delicate balancing act the atmosphere performs, because our atmosphere is very thin, the equivalent to the thin layer of varnish on a 3foot diameter globe.
The ozone layer is a diffused layer and if it were at normal air pressure it would be about 1/8th of an inch thick. It absorbs some 97% to 99% of the Sun’s ultraviolet radiation, if it did not do so all life on Earth would be seriously damaged, yet this layer, depending on the place and the season, is located between only eight to 24 miles high above the Earth.
The problem we now have is that the amount of Greenhouse Gasses, mainly CO2, in the atmosphere has been increased by the use of fossil fuels and the burning of the rain Forests. It really is quite simple; more greenhouse gas equals more heat being trapped in the atmosphere and less escaping into space, what we have done is the same as insulating the greenhouse roof with bubble wrap! It is this increase in trapped heat that changes the climate, altering weather patterns and the greater heat trapped in the atmosphere results in the more frequent and severe weather events that now occur. It is not simply the immediate increase but also the lengthened time scale that this increase occurs over. If for example you insulate the roof of your house the heat does not escape so readily but stays for a longer period. For the Earth then the spring season can start earlier, the summer season extend and autumn arrive later due to the fact that that early and late heat does not escape as it once did and simply builds up within the atmosphere.
Proof of the longer seasons was evident when researchers found that Greenland's annual melting season lasted 50 days longer than average last year when compared to the years between 1979 and 2009. Satellite data indicates that shrinkage of ice sheets may contribute more to sea level rise than was thought. Were the Greenland Ice Sheet to completely melt, which is very, very highly unlikely indeed, then there is the potential of a 5-6 meters sea level rise in the ice sheet which is almost 2 miles thick in the centre.
In Greenland, 2010 summer temperatures of up to 3C above the average were combined with reduced snowfall, and Greenland’s capital, Nuuk, had the warmest spring and summer since records began in 1873.
Greenland’s ice sheet and its melting patterns are quite simply a canary in the climate change coal mine. The canary has started to die, but if action is taken quickly, it can be saved.
Posted by Rev. Peter Doodes at 03:43