more snowfall in Antarctica = more sea level rise, not less

posted by john byatt

Potsdam institute for Climate Impact reasearch

Since snowfall on the ice masses of Antarctica takes water out of the global water cycle, the continent’s net contribution to sea-level rise could be negative during the next 100 years — this is what a number of global and regional models suggest. The new findings indicate that this effect to a large extent is offset by changes in the ice-flow dynamics. Snow piling up on the ice is heavy and hence exerts pressure — the higher the ice the more pressure. Because additional snowfall elevates the grounded ice-sheet but less so the floating ice shelves, it flows more rapidly towards the coast of Antarctica where it eventually breaks off into icebergs and elevates sea level.
“Sea-level is rising — that is a fact”
A number of processes are relevant for ice-loss in Antarctica, most notably to sub-shelf melting caused by warming of the surrounding ocean water. These phenomena explain the already observed contribution to sea-level rise.
“We now know that snowfall in Antarctica will not save us from sea-level rise,” says second author Anders Levermann, research domain co-chair at PIK and a lead author of the sea-level change chapter of the upcoming IPCC’s 5th assessment report. “Sea level is rising — that is a fact. Now we need to understand how quickly we have to adapt our coastal infrastructure; and that depends on how much CO2 we keep emitting into the atmosphere,” Levermann concludes.

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6 Comments

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6 responses to “more snowfall in Antarctica = more sea level rise, not less

  1. Sou

    John, that’s interesting though not at all comforting is it. Here’s a link to the paper in Nature:

    http://www.nature.com/nature/journal/v492/n7428/full/nature11616.html

    You need a subscription to read it but it has some good charts you can look at for free.

    Sou (with a new website – additional, not a replacement.)

    • john byatt

      Sou looked at your additional site, Now where are some of those deniers comments on the coppers site, you have me salvitating

  2. Sou

    Hi John, I was just thinking that I concentrated on HotCopper’s rampant misogyny at the expense of their weird and wacky posts about climate. I’ll see what I can put together over the next day or so. After that I won’t have much time for several weeks.

    Some of them are truly hilarious. Others are mindbogglingly stupid or mind-numbingly boring. Others are frighteningly angry. Denier share traders fall into a few different categories – gives me an idea for a fun angle on my next article :) (I wish I could draw – cartoons would be a great way to send them up.)

  3. Sou

    Hi John, I’ve posted a long-ish article describing a handful of the most prolific deniers. Not sure how it will read – I’m not a natural comedian, having a fairly dry sense of humour. Over time I’ll put up some of the actual comments they’ve made on HotCopper.

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