Climate change

December 15, 2009

Mind the gap – distant climates and immediate budgets

Filed under: Climate Change, Copenhagen, Global Warming, Heat wave — Barry Brook @ 10:56 am

Time for some updates from the world of climate science.

First up, the December issue of Nature Reports Climate Change is definitely worth checking out. (This spin-off internet magazine, produced by the Nature Publishing House, is always worth reading, and you can download a full-colour PDF if you prefer this format — good for printing).

Three articles, in particular, grabbed my attention this issue. The first revisited the premise of carbon budgets proposed by Allen et al. 2009 — a concept I covered in a BNC post back in May 2009. The conclusion was that to have a half-decent (50%) chance of keeping global temperature rise to <2°C below pre-industrial levels, given a climate sensitivity in the range of 2 — 4.5°C, humanity’s cumulative carbon budget between now and ‘forever’ (the next 100,000 years or so), is 1 trillion tonnes of carbon. We’ve burned 500 billion tonnes of fossil carbon and forests already, and on our current trajectory, we’ll break the global carbon bank within the next two to three decades.

In this latest paper, the authors suggest that in order  to better focus our attention to the immediate rather than perpetual task, we need a supplementary short-term budget for the period 2010 — 2030. They calculate that to avoid a rate of change of +0.2 per decade, the carbon ‘expense’ for the next 20 years must stay within 190 billion tonnes, or about 9.5 billion tonnes per year (for context, in 2008 global emissions were 9.8 billion tonnes). If we met this goal, we would then have a further 300 billion tonnes to spend for the period 2030 — 100,2030 AD (or thereabouts). Given the seeming inevitability of emissions growth for at least the next 5 — 10 years, we’ll have to have a serious turn around and decline in emissions in the period 2020 — 2030. Sobering thought. Massive deployment of nuclear and renewable power, anyone?

The second article worth reading is called “Mind the Gap”. Here, the question of novel and disappearing climates is considered (this problem has previously been addressed in the technical literature, here). Take a look at this grim figure:


This is a 4°C warming scenario — what’s expected by mid-century under a business-as-usual approach to fossil fuel use, or the likely climate state by 2100 under a mid-range mitigation scenario (BAU gives up to 7°C by 2100, but let’s  not go there). The grey areas are climates that currently exist nowhere on Earth. The orange-red are areas where the equivalent climate is 6,000 to 10,000 km away. Look again at that map. The grey and orange-red areas are predominant in the tropics. The tropical biomes — mostly humid and wet-dry tropical rain forest, and coral reefs – support over 60% of the world’s biodiversity. Under this scenario, they’re cooked. They’re stuffed. They’ve got nowhere to go. Sure, the tropics are naturally hot, but they’re also stable, with little temperature variation compared to the huge seasonal swings that most of us experience in the temperate realms. This makes well-adapted tropical species acutely vulnerable to rapid change. Crank up the warming ratchet in tropical areas during this century, and the only place these species have to go is back to the Palaeocene. Time machine anyone? I thought not.

The third paper of interest in this issue is an interview with my friend and colleague, Jim Hansen of NASA’s Goddard Institute of Space Studies. He gives is frank and clear assessment of what to expect in Copenhagen, why cap-and-trade is a disaster, and a preview of his new (and first!) popular book, Storms of My Grandchildren: The Truth About the Coming Climate Catastrophe and Our Last Chance to Save Humanity (I was fortunate to read an advanced copy that Jim sent me, and I can thoroughly recommend it — he writes extremely well, and his science is superb).

What else in the world of climate change?  For those readers who  might be interested to hear me on a couple of radio interviews I did this week. In this one, from 5aa Adelaide, I give a frank assessment of Copenhagen. The morning show interviewers, usually a jocular bunch, seemed a bit down after our little chat. I guess I have a depressing effect on people when I’m talking climate change impacts rather than nuclear power prospects! Then, there is a ‘he said… no, he said‘ type of exchange on ABC 891, with an interview with Ian Plimer from Copenhagen, followed by one from me. Suffice to say that, in getting sick of this 50:50 denier vs science cr@p, I let rip.

The World Meteorological Organisation released its annual climate statement for 2009, stating that the decade 2000 — 2009 was the hottest 10-year period on record. This beat the period 1990 — 1999 (yes, 1998 was part of that average), which in turn beat 1980 — 1989. No surprises there, at least to anyone with half a brain. They also report on various unusual ‘extreme events’, including the unprecedented heat waves in Australia, the ongoing melt in the polar regions, intense storm activity, severe droughts, and record sea surface temperatures. Overall, 2009 looks to be heading for the 5th hottest year on record, despite the strong ameliorating effects earlier in the year of La Nina, and the sun bottoming out in a deep and persistent solar minimum. With a strengthening El Niño now coming into play, there is a pretty reasonable chance that 2010 will be the new hottest year on record. We’ll see, but I reckon it’s a better than 50:50 proposition, despite the lack of solar forcing at present.

Finally, if you want to know the reality behind the ‘Climategate’ nonsense (the hacked emails from the Climatic Research Unit of the University of East Anglia), then you must listen to this ABC World Today radio interview with former CRU Director, Prof Tom Wigley (full disclosure — Tom is a close friend and colleague of mine, and we are currently writing a number of papers together — Tom is also an extremely strong supporter of IFR Nuclear power). Despite he and others receiving a number of abusive emails, including quite frightening death threats from social psychopaths, he is keeping his chin up, and explains the situation with candour and dignity. I’ll end this post with a quote from Tom:

ELEANOR HALL: Of course climate change sceptic Andrew Bolt named you as a sort of hypothetical whistle blower on this whole affair. He says that if you weren’t then you should’ve been. How do you respond to that?

TOM WIGLEY: Well there are two things, I mean using the word “whistleblower” is really just another ploy on the part of Andrew Bolt and others to attempt to make it look as though the person who hacked these emails was a good guy and that they had a motive of trying to expose nefarious activities within the Climatic Research Unit.

Well of course there was no such nefarious activities and that’s the reason why what Andrew Bolt has said is just totally ludicrous. He says, “when did Tom Wigley finally choke on all that deceit and if he didn’t why the hell not”?

Well you know, I didn’t choke on the deceit because there was no deceit. All I did was ask a number of pointy questions and I received perfectly adequate answers. It would be really nice if someone like Andrew Bolt used the same approach and tried to get both sides of the picture and then he might learn to understand some of these issues better.

There is also a new ‘Climate Crock of the Week’ video on this issue, called “Smacking the hack attack“. Definitely worth a watch.

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