Even as I sit in the northern hemisphere winter writing this, I am not surprised that 2013 ranked within the top 10 hottest over the 134-year record maintained by the National Oceanic and Atmospheric Administration (NOAA). According to NOAA, 9 of the top 10 years occurred this century.
Because the 2013 ranking is just that – an average statistic – it sometimes seems to be at odds with each of our personal memories about cold and hot temperature spikes that tend to make the news. For instance, many of us heard about a Russian icebreaker that became stuck December 25, 2013 in Antarctic sea ice blown by the winds during the southern hemisphere summer. Many may not know that the rescued passengers were transferred to an Australian icebreaker to be brought back to a region hit by another heat wave. Tennis fans might have heard about when officials suspended several tennis matches at the Australian Open due to extreme heat over 42 degrees Celsius (107.6 degrees Fahrenheit).
Back in the United States, December also provided more extreme temperature stories. Many in the U.S. suffered through a cold blast of Arctic air in December that shattered many daily minimum temperature records in large parts of the continental U.S. Yet that same month, large parts of Europe and Russia experienced abnormally high temperatures. Moscow and St. Petersburg on Christmas Day 2013 surpassed their daily maximum temperature records.
Some wild weather marked 2013, yet when we average them all together to get a glimpse of the climate, the extremes tend to cancel each other out leaving an overall temperature for the year that can be compared with prior years for a long-term trend. Yet the extremes are those weather events we are most unprepared for since the “fat tail” of the bell curve has shifted to a new regime.
We know climate change is contributing to more extreme heat waves. That evidence is solid. Interestingly, a rapidly warming Arctic may also be disrupting air circulation around the North Pole, increasing the risk for wintertime breakouts of cold Arctic air. That evidence is emerging.
Extreme events bring news about heat waves in one place on the globe while at the same time another part of our planet freezes. No wonder it is hard to keep track of the relatively mundane average temperature statistic for the year. Because NOAA and NASA use slightly different baseline years for the average and other slight differences, NOAA ranks 2013 as tied for 4th place and NASA ranks it as tied with 7th hottest.
A profound message emerges when the yearly rankings are binned into decadal averages over a century of record keeping. The slow burn continues.
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