Another day, another angry diatribe from Air Con author Ian Wishart — longer and more intemperate that his last, but I’m getting used to the style. It seems he believes that attack is the best form of defence, which is great if you’ve got the ammunition (like the Crusaders backs of recent seasons, if not this one ), but rather unwise if you lack basic understanding of the issue in contention. I’ll deal with the points he raises, but can’t resist first giving you a flavour of his writing:
I could go on, and on, but I don’t see why I should bear the burden of disproving your half-baked schoolboy science masquerading as genuine informed comment on climate change. I’ve illustrated here that Gareth Renowden’s credibility on climate change, based on his Air Con review, is non existent. Go for it Truffle, crawl back to your den and think carefully before launching ad-hom attacks on me again.
“Half-baked schoolboy science”? Oh the irony, the chutzpah…
Wishart tries to deal with my points on his “icons” of climate change, so I’ll deal with his (long-winded) responses in turn.
…the rest of us know the Arctic is warming in some areas and cooling in others, which the GCMs have been unable to predict or explain, leading many scientists to suspect regional climate trends, not a global one caused by CO2…
This is obviously only true for definitions of “many” that are restricted to single digits. Arctic amplification — faster warming in the Arctic than elsewhere as a result of GHG forcing — has been a robust prediction of global climate models since the 1980s, and is now being observed (Serreze et al. The emergence of surface-based Arctic ampliï¬cation. The Cryosphere Discussions (2008) pp. 11). Wishart then goes on to refer to a recent paper which shows that aerosols and black carbon have an impact on warming in the Arctic. This doesn’t come as any surprise to the climate science community — in fact it’s good news, because it suggests that by taking urgent steps to cut black carbon emissions we can do something to slow down the Arctic warming, which as my original reference points out, is proceeding much faster than expected. For what the Shindell et al paper does and doesn’t say, I prefer to take the word of the lead author (here), than Wishart’s quote from a news item. He expressly doesn’t rule out or minimise the effects of GHGs on Arctic warming.
Assertion two, sea ice extent has decreased sharply. Pathetic. According to the latest May 2009 graph from NSIDC, Arctic sea ice is fast approaching the 1979-2000 average for the first time:
My earlier reference was referring to summer sea ice extent, not early spring sea ice extent, because that’s when warming’s impact is at its greatest. If you visit the NSIDC page that features the graph Wishart uses, you can also read down their May 4 news update to this:
It is difficult to assess how the slow decline through April will affect the summer minimum ice extent. Persistence of cool conditions through the summer could lead to a greater September ice extent compared to that of recent years. However, as discussed in our last post, the spring ice cover is thin and hence quite vulnerable to summer melt. However this summer unfolds, scientists expect to see high year-to-year variability in ice extent embedded within the long-term decline.
It’s worth pointing out that ice condition at this time of year is not a great predictor of where the summer melt season will go, and it’s the summer melt that’s important and has the biggest climate system impacts (see many earlier posts on the subject). Here’s another current graph of ice extent, this time from Japan’s IJIS site:
It shows this year (red) in the context of the previous seven years. It’s obvious that at this time of year, extents tend to bunch together. If you look closely, you can see that the orange line is next highest to this year – and that year (2008) went on to get close to 2007′s record. In other words, showing a graph of ice extent at this time of year tells us little or nothing about “recovery” (or melt, for that matter). I still think the odds on a new record minimum this year are about 50/50 — particularly if you take a look at the ice area graph at Cryosphere Today. Different measure, different shape to the curve, but the fat lady doesn’t sing until September, and I’ll be watching the ice with great interest and my hand on my wallet (only two bets so far…).
On the Northwest Passage: Wishart says in his book: “Roald Amundsen took a ship through it in 1903, as his own diary records.” He helpfully provides a reference, which gives us a few interesting extra details — such as the fact that it took the great Norwegian explorer three years to get his ship through, and that the route he took (the southernmost) was too shallow for big ships. Wishart’s post refers to the St Roch, but only mentions its return journey. On the way out it took 28 months. In recent years, sailors have been getting through in yachts, often through the bigger northerly channel. And in 2008, both the Northwest and Northeast (north of Siberia) passages were open for a short period at the same time!
On bears: I stand by my references. The international organisation of scientists studying polar bears is concerned for the bears future. How the differing populations will react to the full range of factors (which include, of course, whether they’re being hunted or not) remains to be seen, but rapid climate change and substantial loss of ice will not do their numbers any good. That’s why the US lists them as a threatened species.
You have misled your readers by clinging to Steig’s 2009 assertion of the overall warming over 50 years, when we all know, and even the Steig/Mann paper admits, that we don’t have evidence of overall warming since 1980.
It seems Wishart has some trouble understanding what this paper actually says (discussed here). Let’s try and put it simply. Over the full study period (starting in 1957 because that was the first International Geophysical Year, when new weather stations were established around the continent) Antarctica has warmed — all of it. The warming is greatest over West Antarctica and the peninsula. Since 1980, East Antarctica, the largest bit of the continent, has cooled — especially at the centre — but not enough to make it cool over the whole period. Nobody’s really surprised about this, because the ozone hole has an impact on East Antarctic temps (ozone’s a powerful GHG), and as and when the ozone hole heals, we can expect warming in that part of the continent to increase. Interestingly, one of the impacts of increased GHGs in the atmosphere is cooling of the stratosphere, and that helps the destruction of ozone. So the gases that cause warming are also helping to offset that effect deep down South, by slowing down the recovery of the ozone layer where it’s most vulnerable.
Memo to Hot Topic, Public Address and DimPost readers: Antarctica hasn’t warmed overall since 1980, it is dropping in temperature and continuing to do so.
Memo to Wishart. You need to be precise. Warming continues (and fast) in (using your figures) 40% of the continent. You also concede that there’s enough ice there to cause a problem if it melts, and when we look at the latest work, we note that Antarctica as a whole (ie East and West) is losing ice mass. (See Shepherd and Wingham. Recent Sea-Level Contributions of the Antarctic and Greenland Ice Sheets. Science (2007) for an overview, and Rignot et al. Recent Antarctic ice mass loss from radar interferometry and regional climate modelling, Nature Geoscience (Feb 2008) for recent numbers).
Wishart’s post then descends into name-calling and thinly-veiled threats, but he does make one specific reference I’ll draw attention to:
…you know, or should know, that the Argos (sic) project has found no warming from its 3000 robots scattered through the world’s oceans…
Argos? Ahh, I think I get the picture… In Air Con, Wishart cites an NPR radio report to prove his point, but you’ll get a much more nuanced discussion of what actually happened in this Earth Observatory feature. It’s a great introduction to the subject, and is also very relevant to discussions of sea level. Turns out a lot of the “cooling” was down to difficulties with calibrating the new Argo floats.
These are the facts as I see them. They are plainly not the facts as Wishart sees them. Will my attempt to bring some clarity to the issue make any difference? I don’t expect so. His position is not evidence-based, however loudly he may try to claim it is. He has started from an ideological position, and tried to weave a web of carefully selected “facts” to support it. Like a defence lawyer trying to create reasonable doubt in the mind of a jury considering an open and shut case, he relies on his audience not looking at all the evidence, not taking in the big picture.
From another angle, you can interpret Air Con as a work designed to confirm a set of beliefs. Look again at the back cover, and the uncritical acceptance of the book by Vincent Grey (or listen to the Bob Carter audio clip Wishart helpfully provides at his blog). To sceptics and people who share Wishart’s rather odd conspiratorial world view, it’s not important that he be right or wrong. To merely have the book is enough. It becomes a catechism for their fringe beliefs, a book above criticism, above minor considerations of accuracy. It becomes the revealed truth of a fringe religion, a thing to cling to in the face of uncomfortable reality. In the real world, however, Air Con is only interesting as an artefact of a lost cause.