Yes, the climate is getting warmer ...
November 24, 2013
If there was any need to state it, yes the climate is getting warmer. One counter argument was that observational data showed that since 1998 the acceleration was getting slower or, according to some interpretations, did even stop. I will not go into different objections to that but the argument is not entirely fair: climate science talks about a longer period (more like thirty years), but observational data is readily available and published by different meteorological agencies around the world.
However these agencies were also pointing out that important information is missing. I was actually surprised to learn that there were no observations in the global data set for the Arctic. That is understandable given lesser accessibility of this regions (especially for long duration observations), but is nevertheless striking. It is in fact at the North pole that we see one of the most visible effects of global warming, so omission of data from this region is a big gap in our understanding.
Via the UK newspaper The Independent I came across a study by Kevin Cowtan (University of York) and Robert Way (University of Ottowa) that wishes to fill that void. Using satellite data and a clever statistical approach, they propose their results with an almost complete coverage. No surprises: it is indeed getting warmer when you take into account the entire Earth, and furthermore their results are entirely within the initial error margin of the incomplete data. But a graph always says more than words (and sometimes they can even be beautiful, as I wrote earlier)...
There has of course been a little storm on this article by climate contrarians. A nice summary can be found here. There is one point however which I didn't see mentioned by any would-be critic. The two authors aren't really weathered climate scientists. Way is a PhD student in climate studies and Cowtan hails from the Chemistry department, specialising in (digital) feature recognition and image reconstruction.
One should of course know that people outside of the field and expertise have attacked global warning on technicalities (and the same argument has been made for evolution), and they have been rebuked on exactly their lack of credentials. So I think we should be prudent in including without further ado this study as a definite stopgap in our understanding. However, the input from experts from other fields can provide an interesting approach in any scientific endeavour, and should be judged on their merits.
The authors seem to agree. They are quite certain of their results, and see their paper only as a step to advance the discussion. And of course, they have one redeeming aspect in contrast to contrarians: their paper got published after peer review in the Quarterly Journal of the Royal Meteorological Society. So in conclusion, yes we knew already the climate is getting warmer, and here is one more and very probable reason that shows the facts.
@Skeptoid Media, a 501(c)(3) nonprofit