Greenland Ice Cap “Doomed to Meltdown”
Source: New Scientist
The Greenland ice sheet is all but doomed to melt away to nothing, according to a new modelling study. If it does melt, global sea levels will rise by seven metres, flooding most of the world’s coastal regions.
Jonathan Gregory, a climatologist at the University of Reading, UK, says global warming could start runaway melting on Greenland within 50 years, and it will “probably be irreversible this side of a new ice age”. The only good news is that it a total meltdown is likely to take at least 1000 years. [Text continued at site.]
The article mentions that an average temperature increase of three degrees Celsius will trigger the meltdown. If I’ve remembered the conversion factor right, that’s the rough equivalent of fourteen and a half degrees Fahrenheit. In the area I live, the average daily temperature differential is higher than that and there has been a noticeable change in climate during my lifetime.
Many people do not understand that global warming itself is a natural phenomenon. Even without all of the human impact, the world’s average temperature is slowly rising anyway; the human impact is severely increasing the rate of that rise (to extremely dangerous levels) but it is not the sole cause of the rise itself. In geological terms we are still in the very last part of the last ice age. The earth’s average temperature will rise more than that; without the human impact, though, the meltdown would be more likely to last many thousands of years instead of only a single thousand.
There is only a low risk of cataclysmal flooding; such events will be heavily localized and related to the breaching of dikes and earthworks due to the slow rise of the sea. But the biological impact could be tremendous. The rapid change in ocean water salinity will mean that ocean-borne species may not have time to adapt to the new circumstances. The loss of arable land may mean famine throughout the world, for both animal and human alike. (At our present level there is enough food to feed the entire world; the problem is unequal distribution, not supply.) Our species’ recorded history is already several thousand years old; there’s no reason short of something like nuclear war to believe we won’t be around a single millenium from now.
In short, there is ample time to prepare for the ice cap meltdown. There is also ample time to take measures to slow the process back to something more approximating normal. The problem is that the measures need to be started now if we want our descendants to reap the benefits. It is hard to convince people that our actions can cause impact a thousand years later — even in light of a rather obvious but frequently overlooked historical example: the rise of Christianity. I hope we can collectively come to our senses before it is too late.