Will Global Climate Change and Weather Weirdness Impact the Chicago Cycling Seasons?

The mild winter and "summer in March" have been a boon to Chicago area cyclists. Whether global warming was a cause of the warm weather is a source of much debate. According to an analysis by the National Oceanic and Atmospheric Administration, freak chance gets most of the credit for the record warm March weather that gripped two-thirds of the country, with man-made global warming providing only a tiny assist. On the other hand, Jeff Masters of Weather Underground speculates that the loss of Arctic sea ice is an important driver of the strange weather pattern this winter and spring.

Global warming seems to be causing the earth to heat up by about 0.03 F degrees each year. Thus, on a year to year basis climate warming is imperceptable, The big mystery is what impact is the small annual change in temperature having upon local weather. The increase in temperature of only about 0.03 F degrees per year cannot by itself account for the big jump in average temperature that began in December.


The causes of weather are so complex that even with doppler radar and mainframe computers crunching the data, meteorologists still have a tough time getting out an accurate 48 hour forecast. Thus, it is challenging to have much faith in the accuracy of long term forecasts and predictions.


However, global warming may be leading to weather weirdness due to its impact on reduced Arctic sea ice. According to Jiping Liu, a senior research scientist in the School of Earth and Atmospheric Sciences at Georgia Tech;

"We think the recent snowy winters could be caused by the retreating Arctic ice altering atmospheric circulation patterns by weakening westerly winds, increasing the amplitude of the jet stream and increasing the amount of moisture in the atmosphere. These pattern changes enhance blocking patterns that favor more frequent movement of cold air masses to middle and lower latitudes, leading to increased heavy snowfall in Europe and the Northeast and Midwest regions of the United States. If Arctic sea ice declines continues as anticipated by climate modeling results, we speculate that episodes of the aforementioned circulation change will become more frequent, along with more persistent snowstorms over northern continents during winter." 

If the above theory is correct, it would explain why the last two Chicago winters were so nasty and why Europe had such a severe cold snap this winter. However, it does not offer a very satisfying explanation as to why Chicago enjoyed such a mild winter this year. It may suggest that an abnormal jet stream flowing farther north than usual was blocked for an extended period of time. However, if this theory is correct, then it would indicate that the warm temperatures this winter was just a freak abberation in the weather and that Chicago is likely to experience snowy winters during the next few years. I hope that the Georgia Tech prediction that snowy winter will become more common proves to be as inaccurate in future years as it turned out to be in 2011-12

So what's the outlook for the next few months? Most forecasters are predicting a warmer than usual April, but not with the frequency of record setting temperatures experienced in March. This summer is also predicted to be warmer than usual by Accuweather.

On a longer term basis, small annual increases in global temperature may have a big impact on our local weather. It would be good news for Chicago area cyclists if spring starts earlier and fall ends later, particularly if summer temperatures only increase by a moderate amount. Time will tell what future winters hold in store for us.

So far in 2012, the freakish weather has been great for Chicago area cyclists. However, my expectation is that in the next few years weather weirdness and destructive extreme weather events will become increasingly common