Opponents of sensible environmental policies have recently started claiming that global warming stopped some 15 years ago. Thus, according to their logic, we do not need to do anything. It is not entirely clear where this claim comes from but it is a perfect example of how to lie with data and statistics. Anyone with access to the internet can easily prove it to be false.
The average surface temperature of the Earth has been measured since 1850 and is available on the Internet from the Climatic Research Unit at the University of East Anglia. The available data represents the deviation from the average temperature in the years 1961 – 1990. I have downloaded the data and plotted the yearly averages below.
Obviously, the year 1998 was very warm and the temperature has not risen much since, although the years 2005 and 2010 have both experienced higher average temperature (see inset). However, if we consider all the data since 1850, the warming trend is obvious. In addition, it is also clear that there have been periods of 10-20 years with sinking temperatures before. Thus, it makes no sense to claim that global warming stopped in 1998, since, by exactly the same logic, it already stopped in 1938 and 1953. On the other hand and using the same data, one can also demonstrate that global warming has increased significantly from 1970 to 2010. The picture becomes clearer if one considers the 10 year averages, plotted as a red solid line.
Are politicians claiming that global warming has stopped lying deliberately or are they just ill-informed or stupid? I leave it to you to decide. Either way, they have no place in a serious environmental debate.