Twitter Plimer on ice

Okay, so the title of this blog post is rather cryptic, but that’s because I want to quickly talk about three different things. Twittering BNC. Brook v Plimer report back. And the famous disappearing Arctic sea ice.

First then, BraveNewClimate is now producing tweets. You can start following here: http://twitter.com/BraveNewClimate. I’ve also fed the latest 5 tweets on the right sidebar of the BNC blog, below the recent comments list. I’ll use this to feed snippets of interesting information or news that I’ve come across, which relates to the theme of BNC (climate change science and impacts, and sustainable energy for the world), as well as sending out announcements of new blog entries. Feel free to become a Twitter BNC follower, if this part of Web 2.0 takes your fancy.

Second, a brief reflection on that debate with Ian Plimer. It was an interesting night out, which I mostly enjoyed, though it admittedly did fell a bit like a Circus act. The audience turnout was certainly fantastic — a small hall in North Adelaide was packed to the hilt, which made for a great atmosphere. Ian Henschke from ABC Stateline made for a good, fair moderator.

I focused initially on communicating the methods of science and how many small elements come together in a vast body of knowledge that is the science of climate change and its impacts. Plimer then spoke for 10 minutes on the need to consider time (I’d pre-empted him on this), and stated that climate is ‘always changing’ and that the theory that carbon dioxide is causing current change, or has ever caused it, has been falsified. I’ve addressed why this is not the case many times before, and in my rebuttal I made mostly the same points again.

The question and answer session that followed was fairly routine, except for a rather dramatic ‘moment’ involving a poorly phrased  audience question that invoked a sharp retort from my opponent (you had to be there), and some less-than-gentle prodding of Ian by me in order to extract a clear on the question of water vapour’s contribution to the greenhouse effect — which resulted in Ian demanding intervention from the moderator. I’ll leave it to the audience to judge who was in the right. Perhaps some folks who were at the debate can provide their own perspective in the comments below — I know Geoff Russell and ‘John Smith’ already have, in the previous thread.

The end result? An entertaining enough night out, but I doubt anyone changed their minds (a show of hands near the end backs up this hunch).

Alas, although The Environment Institute gave me an .MP3 mic to use to record the debate, the technology failed (I swear I pressed the right button) and so there is no podcast available. I do know that ABC Lateline TV filmed the first hour (I’m not sure if they intend to broadcast anything, or whether it was just for the archives), so there may yet be some hope of us getting a copy of that (we’re looking into it). I’ll report back here if anything eventuates on that front.

Still, as a teaser of more information to come, I’m very pleased to say that a colleague of mine (a well-respected US-based climatologist whose name will is probably familiar to some [many?] of you) was in the audience on Tuesday, and made plenty of notes whilst listening to Ian Plimer’s claims. He is currently preparing a write-up of his major critiques, and I’m happy to say that these will be published on BNC within the next week or so (after he’s finished writing this up). Stay tuned!

Third, the state of the ice — Arctic style. Things are hotting up, literally and figuratively, as the summer melt season now proceeds apace. Recent reports have revealed that Arctic sea ice reached a record low this winter. Key points:

1. February 2009 — the point of the year when Arctic sea ice is at its maximum extent — witnessed a record low amount of [winter] ice, and the extent of re-freezing was dramatically less than the median year.

2. Arctic sea ice continues to thin, leaving about 70% of Arctic ice — up from 40% 30 years ago — as one-year-old ice susceptible to summer melting… ice older than two years now accounts for less than 10 percent of the ice cover.

The 2009 summer ice melt is currently at its second lowest level on record for the end of July. The figure to the right clearly illustrates the melt pattern over the last few years — it is prepared by Philip Sutton of Greenleap (click on the chart to jump to the page, which includes a fuller explanation and a slew of other relevant figures). Brian at Larvatus Prodeo also has a nice article on this. For a technical analysis from the guys at NSIDC, click here.

Now, bear in mind that although 2008 was only the 2nd lowest melt extent on record (bested by 2007), it worringly DID represent the lowest ice volume ever. Each year, the average ice thickness across the North declines, thereby priming subsequent seasons for greater and greater losses. With ‘favourable’ wind conditions, the thin veneer of ice is more readily broken up by storms. More dark water is exposed, aborbing rather then reflecting back the sun’s energy. The amplifying feedback of this climate tipping point becomes ever more inexorable. This is definitely a climate metric to keep watching in the next few months, as the late September melt maximum is approached.