Bayesian statistics, the approach favoured by the IPCC in its assessments of the world's climate, has been ruled illegal by the Appeal Court in London. As the judge explained in a case revolving around possible causes of a fire:
Sometimes the "balance of probability" standard is expressed mathematically as "50 + % probability", but this can carry with it a danger of pseudo-mathematics, as the argument in this case demonstrated. When judging whether a case for believing that an event was caused in a particular way is stronger that the case for not so believing, the process is not scientific (although it may obviously include evaluation of scientific evidence) and to express the probability of some event having happened in percentage terms is illusory.
David Spiegelhalter notes that "[to] assign probabilities to events that have already occurred, but where we are ignorant of the result, forms the basis for the Bayesian view of probability". That being the case, one wonders whether this opens up the possibility of legal challenges to the IPCC assessment reports.
For once, however, I find myself on the IPCC's side. I imagine a higher court will set the ruling aside.