In particular, so-called climate “skeptics” have called into question the hottest year designation, noting that NASA was only 38 percent certain of its conclusion, and NOAA 48 percent sure. Granted, it’s not clear what else they would have the agencies do: NASA only gives a 23 percent chance that the next contender — 2010 — was the hottest, and NOAA only an 18 percent chance. So even if you don’t like calling 2014 the hottest, giving 2010 that distinction makes even less sense.
In any case, now yet another authority — the United Nations’ World Meteorological Organization — has weighed in, also calling 2014 the hottest year recorded. That means that nearly every top science agency that has examined this question — NASA, NOAA, the WMO, and the Japan Meteorological Agency — agrees with the conclusion.
The chief dissenter is the Hadley Center in Britain, which last week demurred and did not clearly rate 2014 the hottest year on record, noting that “the uncertainty ranges mean it’s not possible to definitively say which of several recent years was the warmest.”
The World Meteorological Organization’s analysis, though, tallies together the climate records maintained by NASA, NOAA, and the Hadley Center. The announcement is appropriately cautious, noting that “the difference in temperature between the warmest years is only a few hundredths of a degree – less than the margin of uncertainty.”
Nonetheless, the WMO ranked 2014 as the hottest year, following NASA and NOAA. The overall conclusion at this point, which seems pretty inescapable, is this:
2014 wasn’t a blowout, and wasn’t vastly hotter than all other contenders — but most authorities, examining the data, do consider it to have likely been the hottest year on record. So far.
Here’s a helpful figure from the Carbon Brief, comparing all the different temperature datasets — which, when glimpsed in this way, show overwhelming agreement:
The WMO makes several other pertinent observations in its new statement, including noting that fully 14 of the 15 hottest years on record have occurred in the present century. “The overall warming trend is more important than the ranking of an individual year,” noted WMO Secretary-General Michel Jarraud.
That, at least, is a conclusion with which every scientist studying temperature records would agree.
As have others, the WMO also noted the striking fact that 2014 set a new temperature record without the presence of an El Nino event — a globally twinned atmospheric and ocean phenomenon that tends to temporarily drive up temperatures.
So what now?
There will be ongoing grumbling, and “skeptics” will still try to argue that 2014 wasn’t really that special, and that there’s been little substantial warming between the year 1998 — still one of the hottest years ever recorded — and today.
But most of us, looking at the admittedly noisy record above, will note the trend. And most of us will want our scientists to act and draw conclusions based upon reasonable levels of certainty, while of course admitting their uncertainty — which, in this case, it seems that they’ve done.