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EarthSky // Earth, Human World, Science Wire Release Date: Jul 31, 2014

More heat waves and cold snaps ahead

Climate extremes are here to stay, say researchers.

By now, most sci­en­tists – 97 per­cent of them, to be exact – agree that the tem­per­a­ture of the planet is rising and that the increase is due to human activ­i­ties such as fossil fuel use and defor­esta­tion.

But what about the vari­ability sur­rounding that average increase in temperature? For example, how much dif­fer­ence there will be between the hottest hot days from one year to the next, as well as with each year’s coldest cold days?

The results of a new study by a team of scientists at Northeastern University might suprise some. Their research suggest that while global tem­per­a­ture is indeed increasing, so too is the vari­ability in tem­per­a­ture extremes. For instance, while each year’s average hottest and coldest tem­per­a­tures will likely rise, those aver­ages will also tend to fall within a wider range of poten­tial high and low tem­perate extremes than are cur­rently being observed.

This means that even as overall tem­per­a­tures rise, we may still con­tinue to expe­ri­ence extreme cold snaps, said researcher Evan Kodra. Kodra said:

Just because you have a year that’s colder than the usual over the last decade isn’t a rejec­tion of the global warming hypoth­esis.

The team used com­pu­ta­tional tools from Big Data sci­ence to sys­tem­at­i­cally examine this aspect of cli­mate change. The study used sim­u­la­tions from the most recent cli­mate models devel­oped by groups around the world for the Inter­gov­ern­mental Panel on Cli­mate Change and “reanalysis data sets,” which are gen­er­ated by blending the best avail­able weather obser­va­tions with numer­ical weather models. The team com­bined a suite of methods in a rel­a­tively new way to char­ac­terize extremes and explain how their vari­ability is influ­enced by things like the sea­sons, geo­graph­ical region, and the land-sea inter­face.

The paper was pub­lished July 30 online in the journal Sci­en­tific Reports, pub­lished by Nature.

Read more from Northeastern University