A recent image making its rounds on social media demonstrates that the occurrence of regional cold blasts does not discount human-driven climate change and global warming.

A recent map making its way through social media channels shows global temperature anomalies for the year 2013. Image via @weather_king

A recent image circulating Twitter shows global temperature anomalies for the year 2013 against 2001-2010 climatology. The map, which shows -3 degree Celsius anomalies over North America contrasted with +3 degree increases over wide swathes of Asia, cements the reality that the occurence of regional cold blasts does not reject overall global warming occurring around the world.

To this end, The Washington Post reports that early data suggests that December 2013 was tied for the second-hottest December on record since 1979 and the beginning of satellite measurements, and that global average temperatures for 2013 are expected to be among the 10 highest since 1850. A January 2013 draft report from the National Climate Assessment and Development Advisory Committee explains:

Many scientists do not like the term ‘global warming’ that has been popularly used to describe climate change, because it might imply that it is warming everywhere, which is not the case.  Temperature changes in a given location are a function of multiple factors, from global to local and including both human and natural influences. In some parts of the world, including the southeastern U.S. and the North Atlantic region, temperatures actually fell over the last century. At smaller spatial scales, the relative influence of natural variations in climate compared to the human contribution is larger than at the global scale. Many scientists prefer the term “climate change,” which connotes a much larger picture: broad changes in what are considered “normal” conditions.

This definition encompasses both increases and decreases in temperature, as well as shifts in precipitation, changing risk of severe weather events, and other features of the climate system. At the global scale, it is virtually certain that some future years will be cooler than the preceding year and likely that some decadal periods will be cooler than the preceding decade. Brief periods of faster temperature increases and also temporary decreases in global temperature can be expected to continue into the future. Nonetheless, each successive decade in the last 50 years has been the warmest on record, and the period from 2000 to 2010 was the warmest decade in at least the last 2,000 years. It is virtually certain that future global temperatures averaged over climate timescales of 30 years or more will be higher than preceding periods, and that global temperature will continue to increase throughout the remainder of this century as a result of heat-trapping gas emissions that have already been emitted from human activities, as well as future emissions. Regional and local temperatures exhibit greater variability than global temperatures, but even at a particular location, warming becomes increasingly likely as the timeframe lengthens.

You can also read on: https://www.climasphere.org/#!article/Cold-Snaps-in-a-Global-Context