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Tuesday, April 03, 2007

Climate Change

I’m going to come out of the closet: I am a climate change sceptic.

I can’t deny the fact that the climate is changing… I don’t need a climatologist to tell me it’s getting hotter. What I am not yet convinced of is that human endeavour has had any significant influence in creating or aggravating it.

I’m not saying that I reject the hypothesis that humans have caused or contributed to climate change, just that I am not convinced of it yet.

All of the people I consider to be reliable scientific authorities have come out in support of the hypothesis. While that lends credence to it, none of those people are climatologists, so I don’t really know how much they can be trusted on the issue.

I keep hearing that there is “overwhelming evidence” supporting the hypothesis. While that may well be true, I haven’t seen much of it. What evidence I have seen seems to be circumstantial at best… hardly what I would call compelling.

Perhaps I’ve heard too many Chicken Little stories about killer asteroids, killer flu and killer bees to take it seriously when seemingly alarmist claims are made about the end of the world. Whenever someone starts going on about how mankind is causing its own downfall, my Bullshit Detector starts beeping like crazy.

I think the main reason I can’t overcome this doubt is that whenever someone starts spouting statistics about how much carbon dioxide we spew into the atmosphere and how much the average sea temperature has changed, the biggest piece of information seems to be missing: the baseline comparison.

It seems to me that things like atmospheric carbon content and average water temperature are the sorts of things that tend to fluctuate over time. What hasn’t been made clear to me is what would be a normal, “natural” amount of fluctuation. Apparently these things have fluctuated very little over the last few thousand years, which leads me to believe that we’re due for a change anyway.

Another problem is that there seem to be so many different proposed causes: carbon emissions, methane emissions, ice-cap albedo, solar flares, deforestation and so on. In my experience, whenever a zillion different causes are linked to one effect, those causes are usually all crap.

Before anyone has a panic attack, I do like to pursue, at least in principle, many of the suggestions put forward to help “combat” climate change. Not because I think I’ll be able to make any difference to it, but because they just make sense.

It makes sense to use fluorescent bulbs instead of incandescent ones: they last longer and use less power, which means I save money in the long run. If everyone else did it too, it would allow us to make our limited resources stretch further… I’m all for efficiency.

The same goes for driving Hybrid cars… if they didn’t cost as much as two normal cars, I would seriously consider driving a Prius. When they become more ubiquitous and affordable I will buy one for sure. Again, it’s just a matter of efficiency.

Right, so: I challenge you Chicken Littles – convince me that I should be worried about climate change, but please keep it simple and straight-forward.

6 comments:

  1. I had to look up “circumstantial”, because in a typical moment of etymillogical disorientation I wasn’t sure that I properly understood what it meant. My (one ton) Oxford says that it’s either 1. establishing a conclusion by inference from known facts hard to explain otherwise, 2. given in full detail, 3. depending on circumstances or 4. incidental.

    I goddamn hate this because I get all insecure and disorientated when words that I know that I know I suddenly seem not to know… and then I come across other interesting words that I feel I ought to know, like “cirriped” or “circlip” and I start feeling as though I’d really rather be a tree, or a pebble. Now I have to make sure I understand “inference” and “incidental” too. Tricky things, words. One wrong one and you’re fooked. So gimme a minute here (ok, a day) and I PROMISE to get back to you on this post which you absolutely knew I would not be able to ignore.

    :-)

    PS In the meantime, google “Melanie Phillips” and “Anne Coulter” and ask yourself whether you want to play in their sandpit …

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  2. Ah... the definitions I was aiming at were 3 and 4.

    Yeah, I'm familiar with the Phillipses and Coulters. I know I'm not exactly in good company here. I console myself with the semantical argument that I am not a "denier" or "contrarian", I am merely a sceptic in search of more evidence.

    My frustration was fuelled when I listened to a podcast the other day all about Climate Change scepticism, and the best argument they put forward to combat it was the tired old statement "There is overwhelming evidence to support it" without actually mentioning any of that evidence!

    ARRRGGHHH!

    The thing is I *want* to believe it, but based on the evidence I've seen so far I can't justify that belief!

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  3. Jesus Mary and Joseph. You’re killing me here. I’ve thunk, and I still don’t know what to say. Hayibo. Evolution is still “in debate” in certain circles (and completely rejected in still others as you well know). Their argument is also along the lines of “but there’s information missing”. They’re right, for a given value of “information missing”. And even when evolution is conservatively accepted as a valid theory, the actual understanding of it is often skew and creates bizarre and unnecessary arguments. There will always be information missing, unless you subscribe to the akashic idea which says that there is a vast library of everything that ever was, all recorded faithfully somewhere in the vast ethers, and that all you need in order to access it is a medium (not a small or a large, hey) or your third eye.

    Prognosis – you will be extinct without medication. I prescribe RealClimate.

    RealClimate is brilliant. What they set out to do is build a bridge and that is what they have done. And they proved beyond doubt that scientists also have a sense of humour, with that sheep albedo April fool’s joke (which actually wasn’t so much a joke as a searingly accurate parody of the type of obfuscation that’s all too common out there). They’re all actual peer-reviewed climate scientists, check it out, and they don’t get emotional and fuzzy, even where scientificalists like Michael Crichton are concerned. I’m certain if you hung out with them a bit you’d be put out of your sceptical misery one way or another. It’s for your own good, Captain. Be of good courage! We must live long and prosper, because we want to check out the final frontier don’t we? How on earth (pun not intended) will we do that if we’re extinct, or if all that’s left are a couple of breeding pairs of marketers and mercenaries, plus some assorted Survivor winners?

    BTW, I was in Hermanus in January, and I visited the HMO. Quite cool, the idea that in a vast network of magnetic observatories worldwide, we South Africans are among the few that report to HQ in Japan, and supercool is the idea that the magnetic observatories are actually no-man’s-land of the best kind: dedicated only to science and independent of any political affiliation. Quite Starfleet-esque, in fact. The HMO is in Hermanus but it’s not in South Africa. Groovy. They do all sorts of vitally important stuff there, from navigational (civil and military) to meteorological to climatological to whatever. Anyhow, there were hardly any scientists there when I went, which was a bugger because I wanted autographs etc. They were all in the Antarctic, observing, studying and documenting, well, climate stuff…

    I have to go make supper for waifs and strays now… I think it was Plato who said something about women and men having equal powers of intellect just so long as they were equally freed up from domestic duty… forgive me if I waffle... I’ll be back….

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  4. If Climate Change Theory really is comparable to Evolution Theory then it's cool.

    I've seen enough of the science around evolution to be able to accept that it's a good, solid theory. I know some of the details of it are still in dispute (things like mutation rates, speciation population requirements and so on), but the general idea of it seems to be very reliable indeed, with no evidence (that I've seen) opposing it, and no sizeable holes to speak of (that I'm aware of).

    When it comes to the Human-Advanced Climate Change hypothesis, I see three major pillars to it:

    1. The climate is changing. I don't doubt this part. I can see right here in Joburg how the climate has changed in my lifetime.

    2. The 'Greenhouse Effect' caused by an excess of 'Greenhouse Gases' can result in global warming. I can buy this part as well. I've seen science to back up claims that Carbon Dioxide and Methane in the atmosphere have increased significantly over the last century or so. I've also seen science to back up the claim that those gases appear to be fuelling the change in climate.

    3. Human endeavour (like industry and agriculture) produces large quantities of greenhouse gases. I'm sure we can come up with a pretty good estimate of how many smoke-stacks and cow-farts we have, and thus determine how much of this stuff we produce.

    In order for the hypothesis to work (as far as I see it) these three pillars need to be linked.

    1 and 2 are almost inherently linked... it's a commonsense deducation.

    What I would like to see is the link with 3. Sure, we produce a lot of stuff, but is the amount we produce greater than or less than the amount produced through ordinary natural means?

    In context: how much CO2 does a power plant produce compared to the five ant-nests in its immediate surroundings? 5 million ants probably exhale quite a lot of CO2... is it more than a power plant?

    How many cows have to fart to compare to the combined farts of all the wildebeest in the Serengeti? And how does the ungulate population density of agricultural land compare to that of the same land before it was agriculturalised?

    We may well be producing far more of that stuff than normal, I just haven't yet seen any science to support it yet. If that science exists, please point me to it!

    Forgive my ignorance, but what is the HMO?

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  5. Your original post specifically warned against panic attacks and requested that response be kept simple and straightforward, so of course I had a panic attack and began complicating things at once. But I’m back, for better or worse.

    :-)

    I can’t really point you to all the hard science because it is not accessible to my sandwich brain, and when I look directly at it I just see polka dots on acid. I can try and point you to some of its fuzzy edges, though, and I can even confidently answer at least one of your questions:

    “…is the amount we produce greater than or less than the amount produced through ordinary natural means?” - The amount we produce is greater. The calculations have been done and the budget is known. It should go without saying that the budget also takes into account events like kudu belching, volcanos and solar activity, etc, else it would just be creative accountancy.

    Quick recap for my own sake, oversimplification, sorry: Solar radiation penetrates the atmosphere and is converted on earth’s surface to physical heat, some of which then escapes back through the atmosphere into space. CO2 (and others but there’s a tricksy half-life thing going on which means that CO2 is worst or best depending on your point of view ‘cos it lasts longest) makes a blanket such that enough radiative heat cannot pass back through and gets trapped. Thus we know that CO2 = heating effect.

    OK, so we know too that a heating effect causes more erratic local weather as well as broader climate shifts which in turn are predicted to trigger feedbacks (observable trends have largely followed model-based predictions so far and there’s no reason to think that this will change, specially since there’s an ever-increasing amount of hard data being fed into models which makes the predictions ever more accurate) such as massive methane releases from melting permafrost injecting a sudden extra rise in temp which for various reasons could cause entire forests to die and rot in situ … releasing more massive bursts of greenhouse gases etc and so on.

    One direct link between human activity and the sharp increase of CO2 in the past 150 years can be found in isotope geochemistry. The isotopic signatures of atmospheric carbon bear a quite specific “human fingerprint” that points directly to fossil fuel use – much of it is so “old” that there is nowhere else it could come from. I cannot personally speak about isotopes with authority, but other people can: “…what we find is that at no time in the last 10,000 years are the 13C/12C ratios in the atmosphere as low as they are today. Furthermore, the 13C/12C ratios begin to decline dramatically just as the CO2 starts to increase -- around 1850 AD. This is no surprise because fossil fuels have lower 13C/12C ratios than the atmosphere.” – Eric Steig in 2004. More about the isotope thing, plus references, here: http://www.realclimate.org/index.php?p=81

    There are other links, some direct and some oblique, but the body of evidence is overwhelmingly supportive of the fact that we have largely driven this thing and that it’s picking up speed. While we might not be able to stop it, we can steer it off the road that leads over the cliff. Ugh, that sounds silly. There I go again. Sounds like a politician scraping the barrel. Sorry :-)

    Let me rather quote the IPCC, which uses more conservative language:

    “Much more evidence has accumulated over the past five years to indicate that changes in many physical and biological systems are linked to anthropogenic warming. There are four sets of evidence which, taken together, support this conclusion:
    1. The Working Group I Fourth Assessment concluded that most of the observed increase in the globally averaged temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.
    2. Of the more than 29,000 observational data series7, from 75 studies, that show significant change in many physical and biological systems, more than 89% are consistent with the direction of change expected as a response to warming.
    3 A global synthesis of studies in this Assessment strongly demonstrates that the spatial agreement between regions of significant warming across the globe and the locations of significant observed changes in many systems consistent with warming is very unlikely to be due solely to natural variability of temperatures or natural variability of the systems.
    4 Finally, there have been several modelling studies that have linked responses in some physical and biological systems to anthropogenic warming by comparing observed responses in these systems with modelled responses in which the natural forcings (solar activity and volcanoes) and anthropogenic forcings (greenhouse gases and aerosols) are explicitly separated. Models with combined natural and anthropogenic forcings simulate observed responses significantly better than models with natural forcing only.

    Limitations and gaps prevent more complete attribution of the causes of observed system responses to anthropogenic warming. First, the available analyses are limited in the number of systems and locations considered. Second, natural temperature variability is larger at the regional than the global scale, thus affecting identification of changes due to external forcing. Finally, at the regional scale other factors (such as land-use change, pollution, and invasive species) are influential. Nevertheless, the consistency between observed and modelled changes in several studies and the spatial agreement between significant regional warming and consistent impacts at the global scale is sufficient to conclude with high confidence that anthropogenic warming over the last three decades has had a discernible influence on many physical and biological systems.”

    That’s just one tiny summary-type paragraph from the April 07 IPCC document for policymakers, which is only 23 pages long. Some of the others run to 900… no wonder the policymakers are looking a bit googly-eyed.

    PS Revised prognosis: as far as sceptics go, you’re not the harmful kind as far as I can tell, because you recognise the basic common sense of these three things: change our habits, improve our technology, and adapt to significant environmental changes. But I don’t think you really are one at all, you just need to feel like one because you don’t want to feel like a sheep. 01, you’d better not take it from me, hey. Someone who is presently busy reading A Brief History of Time would be better off reading things like Science and Nature and whole IPCC reports than listening to someone who is presently busy reading The Science of Discworld and Zorro the novel.

    :-)

    PPS the HMO is the Hermanus Magnetic Observatory: http://www.hmo.ac.za/
    Which is part of INTERMAGNET, being the International Real-time Magnetic Observatory Network: http://www.intermagnet.org/Welcom_e.html

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  6. Aha! Something that fits in my head!

    "The isotopic signatures of atmospheric carbon bear a quite specific “human fingerprint” that points directly to fossil fuel use – much of it is so “old” that there is nowhere else it could come from."

    I'm familiar with the use of isotopic geology when attempting to date fossils in paleontology. It didn't occur to me that burned hydrocarbons emitted through the consumption of fossil fuels would retain the same isotopic signature as the source material... but now that I think about it, it makes perfect sense.

    If a significant portion of the atmospheric carbon being tested exhibits this signature, there are very few possible sources of it. Vulcanism could explain it to some degree, but even I don't think there is enough of that going on to compare to the carbon emissions of human industry.

    The rest was good too, but that was the best bit.

    Scepticism largely banished! Thanks!

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