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Scientific American – Polar Meltdown & Scrubbing Carbon Articles

The June 2010 issue of Scientific American had two climate-related pieces in it that I thought were worth discussing.

Polar Meltdown

The first dealt with 12 potential events, their likelihood of occurring by 2050 and some of their effects.  The front cover lists ‘Polar Meltdown’ last among the 12.  The article has ‘Polar Meltdown” as the 8th event, despite its likelihood; I don’t really understand how they decided to organize the events.  I mention these details first because more of the general public reads Scientific American than journals or even climate-related blogs.  Given the nature of the effects – vastly more negative than positive – I would personally prefer to see this listed first both on the front cover and in the article.  Interestingly, their online version has this event first, which is good news.

Another quibble: the picture accompanying the little piece is of Antarctica instead of the Arctic.  In terms of “Polar Meltdown”, Antarctica definitely presents the larger long-term threat of the two.  But the article is supposedly about events by 2050.  I’m a climate realist – which means I recognize that Antarctica won’t completely melt by 2050.  That will likely take a century or two.  And it’s not really even the Arctic ice melting that should scare us all – it’s Greenland.  Greenland’s ice has been land-bound for thousands of years.  When that ice melts, it will raise sea levels.  Similarly for Antarctica – it’s not the sea ice melting every year that presents a threat, its 8 times as much ice as exists on Greenland melting that will raise sea levels even higher.  There are plenty of graphics demonstrating the ridiculously fast meltdown that has already occurred in the Arctic.  They should have shown some of those instead of an Antarctica-shaped piece of ice in a punchbowl.  That’s a lousy visual on multiple levels – the most important being water-borne ice melting doesn’t change the level of the water.  Sheesh.

Okay – onto the science part of this potential event.  Scientific America’s author thinks this event ranks as “Likely”, or better than “50-50″ but not “certain”.  I’m glad to see the assessment at better than 50-50, because it is.  Given the speed at which Arctic and Greenland ice has already melted, I unfortunately think that Arctic sea ice in particular is within a handful of years of disappearing every summer, as this post details.  Arctic sea ice volume is plummeting towards an effective zero point much, much faster than any expert thought possible just a couple short years ago.  If you go to their online version and click on the ‘polar meltdown’ icon, it takes you to a page describing some effects of the event occurring – none of which appear in the print version, by the way.  There is also a place to vote on how likely you think this event is of occurring.  As of this writing, the highest percentage of respondents (36%) agree with the author.  29% of respondents think it is almost certain.  14%, 11% and 8% think it is ’50-50′, ‘unlikely’ and ‘very unlikely’.  There’s freepers everywhere, I suppose.

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New Satellite Data: East Antarctica Also Losing Mass

If the results of the study I’m discussing are robust, and not just true, many more climate change effects will become apparent sooner than many think.  It has been known for a number of years that the West Antarctic Ice Sheet (WAIS) has, on net, lost ice mass since ~2005.  This phenomenon has occurred concurrently with the Greenland ice sheet also losing mass over a similar time period.  That mass loss has contributed to a, until now, relatively small amount of sea level rise.

A new study suggests that sea level rise scenarios may need serious revision quickly: the East Antarctic Ice Sheet (EAIS) has, according to NASA’s GRACE satellite data, also lost mass in the 2005-present time period.  Why is this a potential big deal?  Because east Antarctica contains enough water to raise sea levels by 50-60m (160-200 feet!) if they melted completely.  In contrast, the water in the WAIS and Greenland amount to “only” 6-7m (~20 feet) each if they melted completely.  So the EAIS contains an order of magnitude more water than the other two large ice sheets on Earth.

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