From: Bruce Sterling [bruces@well.com] Sent: Wednesday, March 20, 2002 16:28 Subject: Viridian Note 00302: The Larsen B Ice Shelf Key concepts: Antarctica melting Attention Conservation Notice: To judge by the number of people bringing this story to my attention, you've already heard it. Here's more of it. Links:
Special to Viridian Note 00302: Our acerbic, doom-laden commentary is guest-supplied by the Viridian Curia's own Alan Wexelblat! <wex@media.mit.edu?> "Gotta love some of these numbers... "'A total of about 3,250 sq km of shelf area disintegrated in a 35-day period beginning on 31 January 2002. Over the last five years, the shelf has lost a total of 5,700 sq km, and is now about 40 percent the size of its previous minimum stable extent. "'The Larsen B shelf was about 220 m thick. Based on studies of ice flow and sediment thickness beneath the ice shelf, scientists believe that it existed for at least 400 years prior to this event, and likely existed since the end of the last major glaciation 12,000 years ago.' "(Yes, that's right. We've just destroyed a 12,000- year-old natural feature. Does anyone believe mere cities will survive?) "'For reference, the area lost in this most recent event dwarfs Rhode Island (2717 sq km) in size. In terms of volume, the amount of ice released in this short time is 720 billion tons, enough ice for about 12 trillion 10 kg bags.' "(We're missing the standard pop-science visual image of the size of that stack of icebags. So here's my off- hand estimate: that stack would go from the earth to the moon, back to the earth, and then up to the moon again.) "(To attempt to understand a billion tons is a bit harder. The US consumes approximately one billion tons of oil per year. The entire world consumption of coal was only 4.7 billion tons. During the decade of the 1980s, humans released only about 5.5 billion tons of carbon dioxide into the atmosphere. "(Hmm, no, this comparison isn't doing it. How about this: the entire water consumption by China's population, industry, agriculture, cities, etc. for the year 2000 was 635 billion tons. So global warming just melted 1.1 China-years' worth of polar ice. "(Whenever you search on "billion tons" as a phrase in Google, most of the hits you get back are related to global warming and fossil fuels. There's nothing else for which 'a billion tons' is a normal unit of measurement.)" O=c=O O=c=O O=c=O O=c=O |