Climate model results

From Nasa’s Earth Observatory:News: Greenhouse Gases Cause Northern Winter Warming. Greenhouse gases are the main reason why the Northern Hemisphere is warming quicker during wintertime months than the rest of the world. New climate model results published by NASA scientists in the Journal of Geophysical Research show that greenhouse gases increase the strength of the polar winds that regulate northern hemisphere climate in winter. [NASA’s Earth Observatory]

It’s remarkable that, despite the overwhelming weight of scientific opinion, people who question global warming still get a hearing in respectable circles (the latest offender is the UK’s Sunday Times, which not long ago also gave credence to the dangerous myth that the HIV virus was not the cause of Aids).

4 thoughts on “Climate model results

  1. Steve

    I don’t think that anyone is arguing that greenhouse gases contribute to global warming, nor that we are in a period of warming currently. These things seem true within our very limited time scale.

    But I would argue that the data is not airtight that this is some “new” trend. A lot of data points to previous periods of intense warming of the earth, well before mankinds use of fossil fuels. The continents are still recovering from the effects of the latest Ice Age, perhaps the climate is too. No one really knows

    So, is mankind contributing to global warming? Very possibly. But is this something that can be stopped or slowed appreciably? I think the jury is still out on that.

    I think the only thing that history has shown is that scientists who are absolutely certain they are correct are most often proven wrong.

  2. Brian Carnell

    I think what frustrates those of us who are skeptical about global warming is how interesting scientific studies of climate change become converted into convenient soundbites.

    You summarize this study as saying,

    “New climate model results published by NASA scientists in the Journal of Geophysical Research show that greenhouse gases increase the strength of the polar winds that regulate northern hemisphere climate in winter.”

    But the study’s abstract actually says,

    “This suggests that the AO trend, and a concurrent strengthening of the stratospheric vortex over the Arctic, are very likely anthropogenic in origin.”

    The other thing is that while this study is indeed interesting (and actually confirms some of the skeptics claims as well), like other claims it is based on computer models that are still being refined.

    If you actually read the study, for example, you’ll note that the authors point out, “The primary model used here is an older version of the Goddard Institute for Space Studies (GISS) stratospheric climate model which has an 8- x 10- degree horizontal resolution… While a newer version of the model, with a finer resolution, is available computational resources do not permit us to carry out simulations with that model for the large number of years used here.” (emphasis added). The best they can offer is that the results should stay the same.

    The bottom line is that while a lot of the stuff dug up by people working in climate change is interesting, it is hardly accurate enough at this point to warrant the wholesale changes proposed by some environmentalist advocates.

    One last thing, before you go off doing the “they’re just like the HIV-doesn’t-cause-AIDS folks” you might pause to consider that, as climate change skeptic Richard Lindzen has pointed out, at the beginning of the 20th century it was believed by many people that there was a scientific consensus about eugenics and as a result many parts of the United States enacted laws designed to rid the population of unfit genes, typically by forcible sterilization.

    Which is not to say that this is an argument necessarily against global warming, but that what counts is evidence not consensus. There is a world of difference between scientists who are still skeptical about global warming and those who are still skeptical about the claim that HIV causes AIDS (specifically, the evidence is overwhelming with HIV and AIDS, while all of the evidence for global warming is still largely provisional and based on computer models which are still relatively crude at modeling climate).

  3. Alexandre Takacs

    Unfortunately things are not that simple.

    I guess global warming in itself is hardly debatable. The why is already much more debatable (there are hard evidence that earth has witnessed much more dramatic climate changes without any know reason so far). And no one seriously interested in this field would say the current computer models are anywhere near to produce reliable projections. The whole matter is way too complex for our current understanding.

    That being said a prudent approach is certainly wise (ie. better reduce CO2 emissions even if we don’t have the whole picture).

  4. Brian Carnell

    Lance wrote:

    If, as many responsible scientists have concluded, the evidence for human contribution to global warming is strong, it is irresponsible to wait for incontrovertible proof before we act.

    The problem is that there is only a scientific consensus on one broad claim: manmade greenhouse gases are trapping additional heat within the atmosphere. But what the long term effect of that will be is still anybody’s guess.

    Take a look at this story on an excellent study related to climate change from CNN, Report: Satellite data proves greenhouse effect. These British researchers did an excellent job of finnagling satellite data to demonstrate that less infrared radiation is leaving the Earth’s atmosphere — i.e. the atmosphere is gradually trapping more heat, probably due to manmade greenhouse gases.

    But can we conclude from that world temperatures are headed up as a result? Unfortunately, no. As the lead researcher points out, we won’t know whether it will cause a global heating, a global cooling, or not net change at all until we better understand the role played by cloud cover which nobody is even close to integrating into a reliable computer model to my knowledge.

    This, btw, is also an example of the difference between global warming skepticism and HIV skepticism. I’ve never seen a study by reputable researchers that said, “We know HIV acts this way in the body, but more research is needed to see if it actually causes the symptoms of AIDS,” whereas many researchers on climate change — including the ones who firmly believe that we are causing world temperatures to increase — usually admit that they are still a ways from proving their hypothesis.

    And it makes an enormous difference on whether we should act or not. If average temperatures are going to increase by say 6 degrees Celsius between now and the end of the 21st century you want to do something very different than if average temperatures are going to increase only 0.6 degrees.

    The best approach is simply to wait for more reliable computer models before acting.


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