Does the Hiatus Exist?

A piece by Joe Romm at Think Progress confidently predicts, on the basis of a recent rejiggering of the global warming data by NOAA, that the warming of the planet is about to speed up:

In other words, the long-awaited jump is global temperatures is likely imminent. How big is the jump? As I reported in April, top climatologist Kevin Trenberth has said it would be as much as 0.5°F. Given that 2015 is crushing it for the hottest year on record, we appear to be already witnessing a big piece of that jump.

NOAA’s new study not only incorporates the latest global temperature data from 2013 and 2014. Their “calculations also use improved versions of both sea surface temperature and land surface air temperature datasets” (detailed here). The result, as NOAA explains, is that the new “study refutes the notion that there has been a slowdown or ‘hiatus’ in the rate of global warming in recent years.” In particular, the authors conclude bluntly:

Indeed, based on our new analysis, the IPCC’s statement of two years ago – that the global surface temperature “has shown a much smaller increasing linear trend over the past 15 years than over the past 30 to 60 years” – is no longer valid.

Robert Tracinski at The Federalist explains why Mr. Romm's enthusiasm is at best premature.

The new adjustments are suspiciously convenient, of course. Anyone who is touting a theory that isn’t being borne out by the evidence and suddenly tells you he’s analyzed the data and by golly, what do you know, suddenly it does support his theory—well, he should be met with more than a little skepticism.

If we look, we find some big problems. The most important data adjustments by far are in ocean temperature measurements. But anyone who has been following this debate will notice something about the time period for which the adjustments were made. This is a time in which the measurement of ocean temperatures has vastly improved in coverage and accuracy as a whole new set of scientific buoys has come online. So why would this data need such drastic “correcting”?

In other words, NOAA adjusted the measurements which show a plateau in the global temperature readings and now, mirabile dictu, there's no longer any plateau.

Tracinski offers a lot of reasons to be skeptical of this adjustment, and, if he's right, it does sound very much like NOAA is trying hard to make the data fit the theory of anthropogenic global warming. Nevertheless, whether they are or not manipulating the data there is here an opportunity to see whether the skeptics or the alarmists are correct about what's happening climatologically. Romm says that the alleged "hiatus" never existed but that if it did it's over, that temperatures are about to soar.

Maybe so, let's see what the data show over the next few years. Not only do we have a prediction to test, we also have an opportunity to see whether people on either side of the debate are willing to have their beliefs about global warming falsified. If we're not willing to admit that a belief we hold is shown to be wrong by the evidence then our belief is not a scientific belief. This all assumes, of course, that one side or the other doesn't keep reinterpreting the data until they get the result they want.