The opponents of the theory of anthropogenic global warming have recently drawn much succour from the so called “climate-gate” affair and the discovery of mistakes in the IPCC 4th report. For example, the Liberal MP Dr Dennis Jensen recently called for a Royal Commission into the acceptance of climate science in Australia, on the basis that the evidence for the theory does not itself explain the support by scientists.
His argument is reflective of attacks on climate science, which range from denying there is anything to explain at all (the Earth is not warming; the sea is not rising); claiming that the mainstream science is shoddy (the IPCC is biased; the temperature was higher in the middle ages; so called “climate gate” shows the proponents of global warming have cheated in presenting their data); and arguing that the science is not yet settled and therefore not a reasonable basis for action.
But despite the amount of press given to the recent controversies, each of these claims is demonstrably false.
The Earth is warming, at least according to our Bureau of Meteorology which says that Australia and the rest of the world are experiencing rapid climate change.
Before concluding that this shows that the Bureau’s claims need the scrutiny of a Royal Commission, note that the equivalent organisations in the UK has the same view (PDF 1.55MB).
Also in Canada and the US (PDF 1.44MB).
Similarly the sea level is rising, at least according to the CSIRO. Again, however, before we look for an explanation for the CSIRO’s position, beyond the obvious one that the sea level is indeed rising, note that the National Oceanic and Atmospheric Administration in the US says the same.
As to the IPCC, it has certainly made mistakes in the enormous task of summarising the scientific literature on climate change, which led to a recent review by the InterAcademy Council, a body which represents the peak scientific councils of 15 of the world’s leading scientific nations including Australia. The Review was critical of the IPCC’s organisation and processes, but helpfully rather than damningly so. The first sentence of the conclusion reads:
The Committee concludes that the IPCC assessment process has been successful overall and has served society well.
The Review, in documenting the national origins of the major contributors to the IPCC 4th report, also gives the lie to the notion that the IPCC and climate science generally is a cause célèbre of government funded scientists from wealthy nations, natural allies of green and leftish causes. The Chair of the IPCC is Indian, the Vice Chairs are from Sudan, Belgium and Korea, while the Chairs and Vice Chairs of the working groups that write the reports come from Switzerland, China, Morocco, Iran, Canada, Malaysia, New Zealand, France, the USA, Argentina, Madagascar, the Maldives, Peru, Australia, Spain, Russia, Germany, Cuba, Mali, Sudan, Brazil, Mexico, Italy, the UK and Saudi Arabia!
Given the above, it is should come as no surprise that the science is soundly based on evidence, despite repeated efforts by opponents of climate science to find shonky practices. In particular, the evidence strongly supports the warming trend encapsulated in the famous “hockey stick graph” published by Professor Michael Mann and others. Those who dismiss this temperature record claim it to have been discredited by criticism of Mann’s statistical procedures. It is true that Mann’s methods were the subject of an enquiry by the US National Research Council, held at the request of the Chair of the US Congress Committee on Science, but the results of the enquiry did not discredit Mann’s main conclusions at all.
While the enquiry concluded that little confidence could be placed in Mann’s more precise claims, such as that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium”, it did agree with the more important claim about the overall warming trend: