Geoscience Reference
In-Depth Information
WethenauditedtheIPCCforecastingproceduresusingtheForecastingAuditSoftware
availableonForPrin.com.OurauditfoundthattheIPCCfollowedonlyseventeenofthe89
relevantprinciplesthatwewereabletocodeusingtheinformationprovidedinthe74-page
IPCC chapter. Thus, the IPCC forecasting procedures violated 81 per cent of relevant
forecasting principles.
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It is hard to think of an occupation for which it would be acceptable for practitioners
to violate evidence-based procedures to this extent. Consider what would happen if an
engineer or medical practitioner, for example, failed to properly follow even a single
evidence-based procedure.
We analysed the IPCC's forecasting procedures to assess whether they followed the
Golden Rule of Forecasting. The Golden Rule of Forecasting requires that forecasters
be
conservative
. This means that they should use procedures that are consistent with
knowledge about the situation and about forecasting methods. The Golden Rule is the
antithesisofthecommonanti-scientificattitudethat'thissituationisdifferent,'whichleads
forecasters to ignore cumulative knowledge.
The Golden Rule is a unifying theory of how best to forecast. The theory has been
tested for consistency with the evidence in a review of the literature from all areas of
forecasting that found 150 studies relevant to the Golden Rule. The studies provided
findings from experiments on the effect of conservative procedures compared to
unconservative ones on forecast accuracy. All of the evidence was consistent with the
Golden Rule.
To assist forecasters, the evidence on the Golden Rule is summarised in the form of
28 guidelines, including 'avoid bias by specifying multiple hypotheses and methods' and
forecast error from following a Golden Rule guideline, rather than common practice, is 25
per cent. That is, error was reduced by one quarter.
We found that the IPCC procedures violated all nineteen of the Golden Rule guidelines
that are relevant to long-term climate forecasting, including 'be conservative when
forecasting trends if the series is variable or unstable' and 'be conservative when
forecasting trends if the short and long-term trend directions are inconsistent.' As a
consequence of the Golden Rule violations, the IPCC forecasts are a product of biased
forecasting methods.
Are forecasts of dangerous global warming nevertheless valid?
Having established that the IPCC
forecasting procedures
are invalidated and are
inconsistent with scientific forecasting knowledge, we investigated whether it would be
possible to test the validity of the
forecasts
.
