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Global Temperature Drops Below IPCC Projection Range

Fabius Maximus

Events prove some scientists right, and some wrong. Sometimes the right ones were in the minority.

Watanabe, Nature Climate Change, 2014

Annual-mean time series relative to 1961–1990 mean derived from observations (black), ASYM-H (red) and ASYM-C (blue) experiments. Shading represents ranges of 95% confidence. Watanabe et al, Nature Climate Change 2014

Summary: The climate science debate not only holds answers vital to our future, but allows us to learn from this demonstration of science in motion. Unfortunately activists on both Left and Right have gained control of the public debate, neither interested in the science except to advance their political goals. Here we look at the exciting developments on the cutting edge of the climate sciences.

The essence of science is trial and error, as described by biologist Lewis Thomas in his wonderful essay “To Err is Human”. Scientists form theories and make conjectures. True or false, science either way.  That’s what provides much of its excitement. We see this today in the climate sciences, although journalists too often conceal it from us, preferring the myth of “the science is settled” (now shown to be absurd)..

The pause in surface temperature warming has sparked a new phase of research in the climate sciences. Among other effects, it invalidated several high profile forecasts. Some were informal predictions, such as this by Dr David Viner of the climatic research unit (CRU) of the University of East Anglia, quoted in The Independent, 20 March 2000:

{W}ithin a few years winter snowfall will become “a very rare and exciting event”. “Children just aren’t going to know what snow is.”

Or this, more formal, from the NASA press release “Arctic Meltdown“, 27 February 2001:

… in 10 years’ time, if melting patterns change as predicted, the North-West Passage could be open to ordinary shipping for a month each summer. These predictions come in a recently declassified report of a meeting of American, British and Canadian Arctic and naval experts in April last year, organised by Dennis Conlon of the US Office of Naval Research in Arlington, Virginia. Entitled “Naval Operations in an Ice-Free Arctic” …

Peter Wadhams of the Scott Polar Research Institute in Cambridge agrees that the Arctic could soon open up. “Within a decade we can expect regular summer trade there,” he predicts.

Some projections are both formal and important. The flattish trend of global surface temperatures during the pause has fallen below the lower bound of the projections used by the IPCC (strictly speaking, not predictions).  See the below updated version of Figure 10.1 from the IPCCC’s AR5 WGI from “Contribution of natural decadal variability to global warming acceleration and hiatus“, Masahiro Watanabe et al,Nature Climate Change, in press. The grey shaded area shows projections from CMIP5 (a set of model outputs from the Coupled Model Intercomparison Project Phase 5, used in the IPCC’s AR5). The black line is actual global surface temperature (from the UK’s HadCRUT data).

Watanabe, Nature Climate Change, 2014

It’s a small gap, but might grow to become serious if the pause lasts for years — or even decades (as some forecast). The pause gives us some time to prepare for future climate change — and take measures to reduce it. But we might squander this gift of time. Much depends on the possible political effects of the pause in global warming,

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