Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”
As the U.N.’s Intergovernmental Panel on Climate Change (IPCC) nears completion of its Fifth Assessment Report, it is becoming obvious that not only is the report going to obsolete on the day that it is released, but that it will be dead wrong as well.
We have discussed the implications of the IPCC’s failure to adequately ingest new literature—a failure that results partially from the cumbersome IPCC process and partly because the IPCC doesn’t want to include some findings that run counter to its storylines. The major implication being, of course, that the IPCC reports mislead policymakers around the world, which has a trickle-down effect on all of us who are subject to any resulting policies.
In our post on Monday, we noted the following passage from the “leaked” Summary for Policymakers of the upcoming Fifth Assessment Report:
[Climate] Models do not generally reproduce the observed reduction in surface warming trend over the last 10–15 years. There is medium confidence that this difference between models and observations is to a substantial degree caused by unpredictable climate variability, with possible contributions from inadequacies in the solar, volcanic, and aerosol forcings used by the models and, in some models, from too strong a response to increasing greenhouse-gas forcing. [italics in original]
We were generally pleased to see the IPCC admit that climate models are largely failing to capture the rate of rise (or lack thereof) of the global average surface temperature observed over the past 10-15 years. As we pointed out on Monday, we had written as much ourselves a few years ago.
But, the IPCC went way wrong in this paragraph in which they stated:
There is very high confidence that climate models reproduce the observed large-scale patterns and multi-decadal trends in surface temperature, especially since the mid-20th century. [italics in original]
No, they don’t.