CLIMATE CHANGE UPDATE….The Wilkins ice shelf is collapsing:
A chunk of Antarctic ice about seven times the size of Manhattan suddenly collapsed, putting an even greater portion of glacial ice at risk, scientists said Tuesday.
….British Antarctic Survey scientist David Vaughan attributed the melting to rising sea temperature due to global warming.
….Vaughan had predicted the Wilkins shelf would collapse about 15 years from now.
All the usual caveats apply. However, this is one more data point suggesting that global warming may be happening faster than our current models predict, not slower.
I responded in the comments section:
A few observations.
- Global temperatures have been flat for 8-10 years, after being up substantially the decade previously.
- Recent ocean measurement work as reported on NPR show ocean temps. over last 5-6 years to be flat to slightly down
- 98% of Antarctica has cooled over the last decades and has built up ice pack — 2% has warmed (in the Antarctic Peninsula). I will leave it to the reader to guess where Al Gore sent his cameras
- In August 2007, or about a half year ago, sea ice extent around Antarctica was the largest ever recorded (since measured by satellites in 1979). So, within the last 6-8 months, Antarctica had record sea ice buildup.
Given this backdrop, it is astounding that one could interpret the collapse of an ice sheet that happened faster than one scientist predicted as "accelerating global warming." I can’t think of any mechanism where the behavior of an ice shelf would be a more sensitive measure of the pace of global temperature change than would be the direct measurement of air and sea temperatures themselves.
There are two ways to interpret this ice sheet collapse that are far more "reality-based"
One, the collapse is a result of the fairly well-known and relatively isolated local/regional warming in the Antarctic Peninsula (where I believe this shelf is located). In other words, it signals a local phenomenon rather than a global one, or
Two, the scientist who originally predicted the date of the ice shelf collapse made an incorrect prediction. There is no particular loss of face in this – after all, such events are part of cycles that last long enough that, in many cases, we have not been able to observe even one entire cycle with modern tools. It would be the height of hubris to say that we understand and forecast these decadal and even longer cycles and events well enough to declare that deviation from forecast must represent a change in nature rather than our own poor understanding.
Update: More here via Q&O