Tuesday, May 4, 2010

Physics Works: Global Warming Edition

When people talk about human influences on the global climate, they tend to think that there is much less certainty in the conclusions than actually exists. In fact while the models have a lot of approximations and simplifications, they really do an excellent job simulating the global climate history. You want proof? Behold NASA's really pretty graph (click for a larger version or click here to read the full article):
The dashed line is recorded average global temperature anomaly, which are uncertain to maybe 0.3 degrees C but become particularly reliable after about 1970 when space-based measurements became available. The red line is the average of several global climate models including human influences and the blue line is the average of those same models without human influences. You'll note that almost all of the observed warming does not occur in the models without human influence. All I have to say is WA-BAM! Physics Works!

One other interesting thing to note: the two largest natural influences on climate are volcanoes (labeled and with vertical grey lines) and the El Nino cycle. So it's not that the climate isn't strongly influenced by natural events, it's just that these events don't tend to produce a consistent heating or cooling effect. Humanity, on the other hand, is consistently heating the planet and shows no signs of stopping.


  1. That's really interesting Nick. I'm really impressed by how much volcanos influence things. It's good to see the "human influence" models do such a better job matching the data the the "no human influence" ones.

    However, as I've said in the past, just because global warming is being influenced by humans doesn't prove it is the government roll to crazy over it. (However, I think the government can help in some ways.)

  2. Two scientific evidences against global warming...

    1- It's been very cold here in Utah this spring. We all know climate trends are most reliable when obtained from ones window.

    B- Your graph is the infamous "hockey stick" graph. Well I know something about hockey. First of all, it's played on ice. Ice is cold, therefore no global warming.

    Try to punch holes in that logic Mr. elitist scientist smarty pants! =:)

  3. Nick,

    Nasa makes all the CMB and tools used to analyze it publicly. (Yes if anyone wanted to verify all the WMAP results, all the data and tools are there freely available to do so.)

    Do you know if NASA makes in of their data on global warming and tools they use to analyse it publicly available?

  4. I prefer a warming than a cooling : it is snowing in France currently. May be it can be a great chance for us this warming.

  5. Joe,

    NASA's climate data is publicly available and you can find it at

    The problem with climate data is that unlike WMAP where there is just one data set, for the climate there are literally thousands of data sets and understanding the nuances of each one is difficult even for the experts. But again, the uncertainty is at this point well below the measured and modeled effects of human activity.

  6. Stan,

    Here's some scientific counter-arguments:

    C. Everyone who has ever questioned any aspect of the gospel as preached by Al Gore has been paid off by the global oil hegemony that secretly runs the governments of all industrialized nations.

    IV. I saw "The Day After Tomorrow". Global warming is going to kill us all with giant ice-hurricanes.

    I rest my case. :)


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