Climate science after ‘climate-gate’

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:

It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries.

The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence ...

Mann was again caught up in the so-called “climate-gate affair”, following the release of emails hacked from the Climate Research Unit (CRU) at the University of East Anglia (UEA). Again the deniers of climate change claim these emails show that climate scientists have been colluding to cook their data to support the theory of global warming. But this is not what the four enquiries into the matter have concluded.

The UEA, in consultation with the Royal Society, asked an international panel of seven distinguished scientists, chaired by Lord Oxburgh, to consider whether, in the CRU’s publications, “climatic data had been dishonestly selected, manipulated and/or presented to arrive at pre-determined conclusions that were not compatible with a fair interpretation of the original data”.

The panel reported that:

We saw no evidence of any deliberate scientific malpractice in any of the work of the Climatic Research Unit and had it been there we believe that it is likely that we would have detected it.

A second review, chaired by Sir Muir Russell, looked at the behaviour of the scientists rather than the soundness of their research, examining “the honesty, rigour and openness” with which the CRU scientists acted.

This review did find that:

… there has been a consistent pattern of failing to display the proper degree of openness, both on the part of the CRU scientists and on the part of the UEA, who failed to recognise not only the significance of statutory requirements but also the risk to the reputation of the University and, indeed, to the credibility of UK climate science.

But the review reached this conclusion only after stating (PDF 1.39MB) that:

On the specific allegations made against the behaviour of CRU scientists, we find that their rigour and honesty as scientists are not in doubt.

In addition, we do not find that their behaviour has prejudiced the balance of advice given to policy makers. In particular, we did not find any evidence of behaviour that might undermine the conclusions of the IPCC assessments.

The House of Commons Science and Technology Committee also enquired into the matter. Its report is critical of the CRU and the university, but does not find fault with the science itself. The review states (PDF 312KB):

Consideration of the complaints and accusations made against CRU has led us to three broad conclusions.

Conclusion 1: The focus on Professor Jones and CRU has been largely misplaced. On the accusations relating to Professor Jones’s refusal to share raw data and computer codes, we consider that his actions were in line with common practice in the climate science community. We have suggested that the community consider becoming more transparent by publishing raw data and detailed methodologies. On accusations relating to Freedom of Information, we consider that much of the responsibility should lie with UEA, not CRU.

Conclusion 2: In addition, insofar as we have been able to consider accusations of dishonesty - for example, Professor Jones’s alleged attempt to “hide the decline” -  we consider that there is no case to answer. Within our limited inquiry and the evidence we took, the scientific reputation of Professor Jones and CRU remains intact. We have found no reason in this unfortunate episode to challenge the scientific consensus as expressed by Professor Beddington [UK Government Chief Scientific Advisor - MR], that “global warming is happening [and] that it is induced by human activity”.

Conclusion 3: A great responsibility rests on the shoulders of climate science: to provide the planet’s decision makers with the knowledge they need to secure our future. The challenge that this poses is extensive and some of these decisions risk our standard of living. When the prices to pay are so large, the knowledge on which these kinds of decisions are taken had better be right. The science must be irreproachable.

As for Prof Michael Mann, Pennsylvania State University responded to the release of the emails and subsequent controversy by establishing an enquiry committee, which unanimously concluded (PDF 778KB) that Prof Mann:

… did not engage in, nor did he participate in, directly or indirectly, any actions that seriously deviated from accepted practices within the academic community for proposing, conducting, or reporting research, or other scholarly activities.

These review outcomes where not what the critics of climate science were expecting and they have been rejected on the basis that each of the reviews was a whitewash by mates of the accused. But is this credible?

The House of Commons committee of enquiry comprised two Liberal Democrat members (one in the chair), one Conservative and two Labour members. Only one member opposed the key paragraphs quoted above and others of a similar kind. This one member also opposed the report being sent to the House. That member was one of the Labour members of the committee.

Members of the Oxburgh review included three fellows of the Royal Society including Oxburgh himself and the seven professors comprising the review team, all from world leading universities, spanned the disciplines of physics, meteorology, statistics, mathematics and geophysics.

The Russell review was even more diverse, with Russell having a distinguished career in government and as a vice-chancellor, and the panel including senior professors of geology and physics, the Group Head of Research and Technology at BP, and an independent company director who among other roles chaired the Audit and Management Engagement Committee for an investment trust.

And as to whether the science is settled, the recent summary by the Royal Society documents what is now accepted climate science, what is near to attaining that status, and areas where significant doubt remains to be resolved by further research. Their conclusion is clear:

There is strong evidence that changes in greenhouse gas concentrations due to human activity are the dominant cause of the global warming that has taken place over the last half century. This warming trend is expected to continue as are changes in precipitation over the long term in many regions. Further and more rapid increases in sea level are likely which will have profound implications for coastal communities and ecosystems.

Likewise, the Australian Academy of Science report released earlier this year, The Science of Climate Change: Questions and Answers, began with this statement:

The Earth’s climate has changed. The global average surface temperature has increased over the last century and many other associated changes have been observed. The available evidence implies that greenhouse gas emissions from human activities are the main cause. It is expected that, if greenhouse gas emissions continue at business-as-usual rates, global temperatures will further increase significantly over the coming century and beyond.

The recent report from the National Academies of the US is even more direct:

Conclusion 1: Climate change is occurring, is caused largely by human activities, and poses significant risks for - and in many cases is already affecting - a broad range of human and natural systems.

Finally, the Encyclopaedia Britannica has published Climate  Change: an unbiased guide to the key issue of our age, which gives useful scientific background as well as summarising the conclusions reached in greater detail by the IPCC.

Clearly, the basic science of climate change is settled.

This is not to say that every fact about climate or weather is now explained by the theory. That would mean that the science was finished rather than settled. Nor is it to say that the science is certainly true.

Perhaps at some time in the future our current understanding of basic physical processes in the atmosphere, for example, will be overthrown by some new theory, as Einstein’s theory of motion overthrew Newton’s. But important though it is to acknowledge that science is fallible, this is true for all scientific theories rather than being a fact about climate science in particular. The fallibility of science does not stop us building bridges, or flying in aeroplanes, or taking therapeutic drugs. Neither should it stop us taking action to deal with the warming our current best understanding of the physics, chemistry and biology of the Earth and its atmosphere says is happening and will accelerate if we do not urgently move our economies to a low carbon future.