Watts Up With That (WUWT) has a new post by our old favourited Christopher Monckton. It’s called Ten years of ‘accelerated global warming’?. In this post Christopher attempts to address Barack Obama’s claim that over the past decade global warming has been accelerating at an unforeseen rate.
Let’s first establish what Obama used to make this claim. It’s essentially based on recent Ocean Heat Content measurements that extend down to a depth of 2000m. The figure below is from Balmaseda et al. 2013 and shows the Ocean Heat Content for the period 1955-2010 and for depths down to 300m, 700m, and 2000m. This figure indicates that the from 2000 to 2010, the total (or at least down to 2000m) Ocean Heat Content increased by 1.5 x 1023 J. This is the largest decadal rise in the dataset. If one uses this to establish what the top-of-the-atmosphere energy imbalance would need to be to produce such a large increase, it is about 0.9 Wm-2. This is a remarkably high energy imbalance. It is typically been measured to be about 0.5 Wm-2.
Okay, so that is what Obama was using to suggest that global warming has accelerated in the last decade. What does Christopher Monkton do to refute such a claim. Does he suggest that there are problems with the ARGO floats used to collect the data? Does he argue that the uncertainties are large and that we shouldn’t be making such strong claims using this data? No, he completely ignores the Ocean Heat Content data and focuses only on those dataset that provide surface temperatures (GISSTEMP, HADCRUT, NOAA) or tropospheric temperatures (RSS, UAH). So, he tries to refute Obama’s claim by using temperature datasets that measure the temperature in regions that are only associated with a few percent of the current warming.
There is plenty of evidence to suggest that at least 90% of the excess energy entering our climate system is currently going into the oceans. Given that so large a fraction of the excess energy is going into the oceans would seem to indicate that you should at least consider this when making claims about whether or not global warming is happening. Focusing only on surface temperatures would seem to indicate that either you don’t understand (or don’t want to understand) what the term “global warming” actually means.
Now, I don’t know for certain that global warming has actually accelerated in the last decade but there is clearly quite strong evidence (in the peer-reviewed literature) that it has. Obama therefore based his claim on a perfectly reasonable bit of scientific evidence. Monckton is refuting this by cherry-picking datasets that virtually no reputable scientist would regard as reasonable indicators of global warming.