Two stories crossed my path this week both concerning ice in the antarctic, and taken together they form an interesting commentary on the drama, the challenges, and the context – of climate science.
The first story was a regular update from NASA’s Earth Observatory on the disappearance of the Larsen B ice shelf in 2002. I have made a composite picture (above) of the ice shelf before its collapse, and its absence after its collapse. There are articles describing:
- The shocking rapidity of the collapse – it took just 10 weeks at the end of a warm antarctic summer to lose a structure that had probably been there for millennia.
- The debris hung around the bay for 3 years, but eventually left the bay clear of ice in summer.
- The retreat of a glacier which fed into the place where the ice shelf had been.
The cause of the collapse? Well it was probably the melt ponds (visible in the left-hand satellite picture above as blue streaks) caused by an anomalously warm summer. The theory is outlined here. Taken together they form an interesting commentary on the drama of events in the antarctic.
The Register also had a story about scientists extracting Ice Cores in this area to see if there was anything anomalous about the Ice Shelf collapse. The Register story is simply a re-hash of a press release from Eureka – the press agency of the American Association for the Advancement of Science. I find it interesting to see just how little the author has bothered to change. I also note that he has failed to quote his primary source. At face value, it is an interesting commentary on the challenegs facing scientists trying to understand events in the antarctic – the work is just hard and everything breaks when it gets cold!
Now The Register is not so much climate sceptical as climate cynical in a typical juvenile manner. And so they have to get in a few jibes about how really scientists don’t understand what is happening and how the Larsen Ice Shelf Collapse is anomalous. However, it is not actually that uncommon according to the NASA articles. And they have to throw in a confusing ‘factoid’ to make it seem that really there is no evidence for anthropogenic climate effects. In this case they throw in the fact that while Arctic sea ice cover is declining at 4% per decade, Antarctic sea ice cover is increasing at approximately 1% per decade. These facts arte presented like they are some way ‘equivalent’ and so cancel each other out on some kind of climate ‘factoid’ debate.
You can read about the facts here. Its a great page, full of information not amenable to soundbites. But the summary graph of the arctic and antarctic sea ice extent is given here:
Now I have analysed a few graphs in my time and the red line looks to me to be barely above statistical significance. I have written asking for the data so I can establish an uncertainty on that slope.
Taken together these, different aspects of the ‘story’ illustrate concisely the challenging context in which scientists trying to understand events in the Antarctic have to work.