Global Warming: Causation vs. Corelation

By Daniel Miessler on March 16th, 2007: Tagged as Global Warming | Science | Statistics

In science, one of the most elusive issues is that of causation vs. corelation. In other words, how do we know if a actually caused b, or if a and b just happened to be going on at the same time in a seemingly related fashion?

An interesting article at National Geographic is claiming this is what’s going on with global warming. In short, the argument is that increased solar output is to blame for the recent heatup — and not greenhouse gasses.

So while they agree that greenhouse gasses do increase heat, they’re saying it can’t account for near as much as what the sun could do with just a marginal increase in output. Makes sense to me. But the really compelling part is the fact that the ice cap on Mars has seen increased melting for three summers in a row — just like ours — a fact that’s obviously not related to our stupidity.

On one hand I’d be happy to find out we aren’t causing this problem, but on the other I’m afraid we still are, and that this will cause many people who were considering solid environmental programs to abandon them. They’ll basically just say…”Eh…turns out it wasn’t us afterall…crank up the coal plant, Bob!”

I look forward to seeing more debate given this new information.

(Thanks to Ken for bookmarking the article)





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2 Comments »

  1. Personally, I’d have to say that I wouldn’t be placing bets on this hypothesis.

    If you read onto page 2 of the article, it does say:

    “His views are completely at odds with the mainstream scientific opinion,” said Colin Wilson, a planetary physicist at England’s Oxford University.

    “And they contradict the extensive evidence presented in the most recent IPCC [Intergovernmental Panel on Climate Change] report.”

    As well as:

    “Perhaps the biggest stumbling block in Abdussamatov’s theory is his dismissal of the greenhouse effect, in which atmospheric gases such as carbon dioxide help keep heat trapped near the planet’s surface.”

    The article (on page 2) also explains “planetary wobble” as a very plausible counter-point to this single study from this single man. Not that I distrust the ability of one man to change how everyone looks at the universe, it’s just that I doubt that this is the case here.

    http://realclimate.org/ has some educated response to the “it’s solar!” argument, among other counter-points.

    The thing that makes Anthropocentric Global Warming a Theory is that it is so well supported by many different facts, collected by many different scientists; all peer-reviewed and scrutinized. Of course the science is open to interpretation, and if there were enough evidence to warrant revising AGW, then I doubt scientists would have any issues with doing so. The problem is that they (climate scientists) have a lot of correlating data that leads them to dismiss, or at least marginalize, the solar factor.

    As you noted, even if C02 turns out to be relatively innocuous as a global warming agent, we still must be looking to harvest all of that abundant solar energy being poured onto the planet in ridiculous excess, instead of burning fossils; it only makes sense.

    :-)

    Comment by Allan Haggett — 3/17/2007 @ 3:43 am

  2. There is an answer to the Mars warming on the ‘How to Talk to a Global Warming Skeptic guide’. See also the link to realclimate in that post.

    Thing is, it is not just correlation that leads to the theory that it is the greenhouse gases that lead to warming. We also know how it worls. I have already wriiten this in a comment:

    The important thing is that we know how greenhouse gases affect climate. It has even been predicted hundred years ago by Arrhenius. It is simple physics. In a nutshell: The sun radiates mostly in the visible spectrum, for which CO2 is transparent. The same amount of energy has to be reradiated back to space by the earth. Ideally, the sun and the earth emit a black body spectrum. Because the temperature is lower, the earth does this mostly in the infrared spectrum. But for IR, CO2 is not transparent, so it absorbs the radiation coming from below. It also reradiates it, but in all directions, and half of this back to the surface. This mechanism is well known, and has been for a long time. Furthermore, climate models, which include much more complex physics (including changing sun radiation, vulcanic eruptions, ozone, sulfate polution) show the same behavior: temperature rise with CO2, no rise without. It’s the next best thing to doing experiments (we do not have enough time and a few dozen spare earths to do experiments with…). See for example this graph. And, other data also confirm that it is indeed a greenhouse effect and not an external factor like increased sun radiation: the lower athmosphere is warming while the upper athmosphere is cooling; and night time temperatures rise more than daytime temperatures. Both effects are predicted by the greenhouse effect.

    I also recommend to read the IPCC report.

    As for the solar factor, this is not marginalized at all. It is part of the model, but it turns out that it is a small factor compared with the forcing of the greenhouse gases. Other, indirect mechanism are investigated as well, but so far nothing that withstands further investigation has been found. Search for ’solar activity’ and ‘cosmic rays’ on realclimate.

    Sorry for the long comment…

    Comment by fermiparadox — 3/19/2007 @ 7:31 am

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