In 2007, I published this column over on my Newsvine channel in response to a particularly egregious bit of science-twisting by some climate change deniers at the time. With the recently released IPCC report, and some other excellent studies solidifying the anthropogenic nature of mechanisms underlying climate change, it seemed like a fun time to re-post this piece.
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| SOHO image courtesy NASA/ESA/EIT. |
Recent statements that we have data suggesting that the whole Solar System is warming are not accurate. However, I understand how some were led to this misconception, mostly by anti-global-warming types spinning a few honestly neutral stories to sound like our whole solar neighborhood is practically awash in flames. You see, now that this crowd has figured out they can no longer believably deny the existence of global warming, they have turned to muddying the "whodunit" waters. Having been intimately involved in an active planetary science research program, let me give you some facts, de-spun.
Let us take an exemplar of this crowd, Cato Institute favorite Luboš Motl, whose blog "The Reference Frame" can be found here. Mr. Motl elaborates, planetary body by planetary body, upon how the solar system is warming -- implying that it's the Sun's fault all the way 'round, including on Earth (and thus absolving humanity from responsibility). Motl's mischaracterizations range from the blatant to the almost impressively subtle, so stay sharp here.
Take a couple of the planets he discusses. He says: "Venus, our planet's evil sister, has already been identified as unusable for life because of ... yes, because of the greenhouse effect that occured [sic] in the past. Last month, the Venus express gave us some new hints why Venus has such a thick atmosphere that generated global warming." [Quote is not edited down, the ellipses are his.]
This is very sneaky wording. While it is true that Venus is "trapped in a runaway greenhouse effect," we have no data either way about Venus' climate throughout history, nor projections about its future climate. To clarify the terms here (which are somewhat confusing), perhaps it would help to think of Venus as having a *ran*-away greenhouse effect: the climate "ran away," enough to establish the current climatic regime. But we have no data about whether it's still "running." We have no reason to assume that Venus' current climatic regime isn't a completely stable one which will last into the foreseeable future. The adjective "runaway" is used here only to indicate a severe or extreme case of greenhouse-style planetary warming, *not* anything about a future trend. In short, we only know where Venus is today, we know nothing about where it is going (and very little about where it's been). Motl implies with his vague wording that Venus supports his thesis that the whole solar system has been warming up lately. He carefully says nothing incorrect -- note that he says the warming occured "in the past", but doesn't specify that we found Venus just like it is with our first probe (Magellan) thirty years ago.
Yes, Venus warmed up at some point, but "in the past," not as part of a recent warming trend as he implies. Or at least, we haven't had two sets of observations to compare in order to make such a judgement, though he implies we do, now that the Venus Express has arrived (more sneaky wording). He makes it sound like Venus Express has found the planet has warmed since our only other visit, when in fact the probe has been there so briefly, no verified data has yet been released. In reality, one of Venus Express's main objectives is to see if perhaps Venus has always been warm, and it was actually Earth that cooled down long ago (see especially paragraphs 17-20 here).
Of Saturn he says "Saturn itself has a rather warm southern pole, and the temperatures in that region suddenly jumped by 3-5 Kelvin degrees. Well, it's warm because it's been exposed to sunshine for quite some time but the magnitude of the temperature jumps is not trivial to calculate." He even admits here that the pole's warming is because of how long Saturn has been facing one direction, and is actually an expected outcome of this orbital oddity. Motl obfuscates this fact by protesting at the difficulty of the calculation, but carefully avoids saying the results suggest the temperature jump isn't caused by the planet's orientation (because that's not the case). However, Motl is happy to let you think it does. More "linguistic legerdemain," as Mr. Spock would say.
Motl notes that Saturn's moon Enceladus has warmed more than expected, even admitting that the Cassini probe indicates Enceladus possesses an internal furnace and "generates its own heat." Total non sequitur, here, folks – if Enceladus generates its own heat, then how does the moon support his argument that the Sun is heating up the whole solar system?
Motl takes USA Today's article trumpeting climate change on Jupiter as something worth reading – does anyone read this paper for actual science?!?! – and proudly points out that "nothing less than global warming is expected." If you read an article that actually describes this research, you'll see how improper and even ridiculous using this to support his conclusions really is. Nowhere, nowhere at all, does the research suggest the warming is caused by increased solar activity – quite the opposite ("Jupiter generates much of its heat from within"). All the research says is that some fluid mechanics modeler somewhere (who has "never looked through a telescope") built a computer model trying to explain/predict Jupiter's notorious storms. His modeling is based on qualitative information, *not* quantitative information (i.e., data!), and furthermore all he found is that the current system of storms seems to be in constant flux, and may collapse soon. As the storms keep Jupiter's total heat well-distributed across the planet, any such collapse halts this distribution system, allowing heat to build up in certain places like the equator. So, yes, the research suggests the *equator* might get hotter, but (a) that is not "global warming" (i.e., there is no suggestion that the whole Jovian globe will warm 1 degree K on average, only that heat will be poorly distributed), and (b) let me reiterate, the model does not imply increased solar heating!
Stick with me here, let's look at one more, Mars. It's important because there are many more articles out there about Mars, with many more distasteful spins. Stein Sigurdsson fields this one very well in about one well-cited page. The gist is that, completely contrary to right-wing spins (and Motl's assertions), all available climate data for Mars shows the atmosphere *cooling* over the past 30 years. Motl cites a recent study that Martian South Polar ice seems to be retreating as evidence of Martian "global" warming, but it is actually a well-known fact that the Martian south pole has wonky geometry/ topography that leads it to behave in slightly oddball ways compared to the rest of the planet. In Sigurdsson's words, "Colaprete et al in Nature 2005 showed, using the Mars GCM [Global Climate Model], that the south polar climate is unstable due to the peculiar topography near the pole, and the current configuration is on the instability border; we therefore expect to see rapid changes in ice cover as the regional climate transits between the unstable states. Thus inferring global warming from a 3 Martian year regional trend is unwarranted. The observed regional changes in south polar ice cover are almost certainly due to a regional climate transition, not a global phenomenon, and are demonstrably unrelated to external forcing." Motl goes on to provide more amusing contortions for other planetary bodies, but for the sake of not going on even longer than I already have, I'll tell you their treatments are just as disengenuous, and leave it at that.
Right-wing think-tanks like the Cato and Heartland Institutes have seized upon many of the same things as Motl to build a case that solar activity is causing solar-system-wide warming trends. They then argue that since it's not humanity's "fault," there's no point in altering our greenhouse gas production. What's really screwed up here is, regardless of whether global warming is being caused by us or the sun, *either* one is a huge problem, both with the same solution: cut CO2 production! If the sun is indeed heating up the neighborhood, how do we save the planet from toasting to a crisp? Throw off the blankets, baby – decrease CO2! In fact, if Motl's implications are correct, and the Sun is the culprit, then we have an even bigger carbon problem than before: we would need to decrease CO2 in the atmosphere to **below** the natural, pre-industrial norm. That's right, we would need to not just halt our production of CO2, but remove every molecule of it we ever put up there, and then a heckuva lot of what was up there before we ever started the first man-made fire, to boot. It's great when arguments are so bad that they defeat themselves.
Oh, and "one more thing, " dear commenter. To your credit you didn't go there , but there is a final fallback position for the anti-anthropogenic-global-warming crowd that I want to head off at the pass: that old "we're saving ourselves from the next regularly-scheduled ice age" argument. On the face of it, that may in fact be true: we are about due for an ice age, and maybe, just maybe, we've put it on hold for the time being with our extra greenhouse gases. But at what cost? We know approximately what we would be saving ourselves from – but what would we have screwed ourselves into? (For more detailed discussion of this specific sub-topic, visit the Woods Hole Oceanographic Institute's website, for excellent articles such as this one).
The key to answering this is an understanding of the nature of cycles such as our climate's sinusoidal one. The cycle is like a clock pendulum: if you force it out of its equilibrium by yanking the thing to one side, does it immediately return to its natural swing? No. It will first swing back nearly as widely to the other side, then swing back almost as widely as that to the first side, etc., until it regains equilibrium. This is an excellent analogy for a self-regulating system like Earth's climate cycle. That is, unless you pull the pendulum so far back that when you let go it smashes itself to bits on the other wall – another apt analogy. We don't know where the limits are to what our self-regulating climate system can take, but all self-regulating systems have such limits. This means the result of our futzing with the system has two possible outcomes: (1) a continued heating that will track our carbon emissions, breaking the climate cycle past its ability to right itself, sautéing us slowly, slowly to the Venusian death of our civilization, or (2) we won't have broken out of the cycle's ability to self-regulate, and we'll see a temporary (on the order of a few hundred years) average temperature spike which will screw things up royally, followed by an equally dramatic downswing which will freeze things just as royally, on and on, pounding our civilization for millennia until finally equilibrium is regained in a million years or so. If these folks think civilization is in danger from your regularly-scheduled garden-variety ice ages, the ones that occur when the system is "in" whack, they are in for a rude awakening about what happens when the system is thrown completely out of whack. This is all basic thermodynamics, as irrefutable and inexorable as entropy itself.
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