Saturday, November 26, 2011

Do-It-Yourself Global Warming Simulation

   I thought of a new way to visualize the ravages of global warming.  According to the best models put forward by the Intergovernmental Panel on Climate Change (IPCC), the average global temperature will increase by about 2 degrees Celsius by the the year 2100.  How will that feel to your ancestors?

    One way to simulate that would be to compare the climate that you experience now, with one that is further south.  Referring to the map of the US, The farther north you are, the colder the average temperature is, so that in the northern US some parts have an average January temperature of 20 degrees Fahrenheit, whereas down in Florida, some 1000 miles to the south, the average temperature may be some  60 degrees F.  The difference is 40 degrees F or some 22 degrees C.  In rough terms, if you drive south 50 miles it is going to be about a degree warmer.  You need only drive about 100 miles south and you will experience the difference in climate.  

     For example, if you live in Indianapolis Indiana, you can drive down to Louisville, which is five degrees warmer (F) on the average.  That will allow you to internalize what Global Warming is really going to mean to your descendants. 


    Now, of course I am not being quite fair.  In addition to the average temperature, climatologists are now saying that the real problem is going to be something called "climate change."   This is only now starting to even be defined.  But basically they are saying that the weather is going to be more variable, and that there may be more hurricanes, tornados and other events.  As a scientist, I look forward to seeing numerical predictions before further commenting. 
    But I have a feeling that humanity will survive this, or at least I'm less concerned about surviving global warming than surviving extreme politicians.  


  1. Another question I have thought about is whether the Little Ice Age was real or not. History records that the Thames River used to freeze over regularly, and Charles X marched an army over the Baltic Sea from Sweden to Estonia. All this while the global average temperature remained within 0.4 degrees of the 20th Century average? In other words the cold was nothing more severe than what would be experienced some 50 miles or so futher north?

  2. I don't think anyone is suggesting that global warming is an existential threat to humanity (but it might be to individual humans (though, sub-parenthetically, least of all to North American humans)).
    But I struggle with your analogy, if variability increased it would take larger temperature extremes over much smaller intervals to change the overall average. Those brief intervals are what would would matter, particularly to climate sensitive plants. I also think the 50 miles south notion is not so useful near poles and the equator.
    I don't think the Little Ice Age is particularly real in the sense that the dramatic documented events varied considerably in time from place to place. If anything, the naming of such a diffuse event, supports the notion that seemingly trivial changes in mean temperature can have profound less-than-existential consequences.

  3. Hi Chick, thanks for stopping by. There is a very real postulated threat that global warming might be lead to "runaway" temperature rise, and this is the reason why the world is willing to consider drastic reductions in the production of fossil fuels. If you will google "runaway global warming" you will see that many people take that threat very seriously. There is also a widely belief that a temperature rise of 2 degrees would itself be a severe consequence, particularly if (as you say) it is amplified in polar regions. But I think the threat of climate disaster has to be balanced against the threat of economic disaster. Either one could be triggered inadvertently by human actions.