At least, I hope it is thinking again about this subject: it is apparently planning to issue a new version of its ‘Science of Climate Change’ statement in the middle of the year. When I noticed that the American Physical Society was planning a rewrite of its own statement I wondered what the AAS was doing and set off to find out. The APS set up an advisory group to help it, and that group included three distinguished sceptics, including Professors Lindzen and Curry.
To the best of my knowledge, the Australian Academy has not done that, and my telephone has received no inviting calls from the AAS. Well, I thought, I could still prepare something, and the Academy might even welcome some advice from the side. Surely it will be preparing an even-handed dispassionate review of the science behind ‘climate change’, so I looked at the 2010 Statement that is to be replaced, and at what might be improved there.
It was not exactly a reassuring beginning to discover at once that the Academy had thanked ‘the Department of Climate Change and Energy Efficiency for providing financial support to prepare this document’. That was when Mr Rudd was in charge of things, and Mr Rudd, as we all know, thought that ‘climate change’ was ‘the greatest moral, economic and social challenge of our time’. Am I being too suspicious in wondering whether a completely even-handed account of global warming and its possible consequences would have secured the Departments’s financial support in 2010?
The 2010 Statement is built around seven questions: what is climate change?, how do we expect climate to evolve in the future?, how has Earth’s climate changed in the distant past?, how has climate changed in the recent past?, are human activities causing climate change?, what are the consequences of climate change?, and how do we deal with the uncertainty in the science?
After reading the Statement a couple of times I came away with the hope that the Academy gets a good writer to draft the next version. This one is hard going. The main reason is that each section says plainly enough that there is a lot of uncertainty in all this climate science. Consider this summary:
There are uncertainties in climate science. For example, a precise value cannot be
given for the likely range of warming because of uncertainties in climate sensitivity to small disturbances, although climate models and evidence from past climate change provide a plausible range of values. Climate changes over small regions and changes in rainfall patterns are very hard to estimate. Tipping points or rapid climate transitions associated with overall global warming are possible but cannot yet be predicted with confidence. These uncertainties work in both directions: there is a chance that climate change will be less severe than the current estimates of climate science, but there is also a chance that it will be more severe.
There is a lot of this ‘on the one hand, but on the other hand’ throughout the statement. Yet the take-home message in every other paragraph is remorseless: climate change is really serious and we have to do something about it quickly. Where is the evidence? Well, it’s hard to find. Again and again what we come across is what ‘the models’ say, as here:
Climate models estimate that, by 2100, the average global temperature will be between 2°C and 7°C higher than pre-industrial temperatures, depending on future greenhouse gas emissions and on the ways that models represent the sensitivity of climate to small disturbances. Models also estimate that this climate change will continue well after 2100.
It’s been a long while since I saw that 7°C figure put forward seriously by anyone. I assume that it will disappear in the next version. And even the models come with their own uncertainties:
Models simulate reasonably well the broad features of the present climate and the 20th century warming. This, however, does not guarantee accurate predictions into the future; changes could be more rapid or more gradual than projected. Overall, there is good agreement between models and observations at global and continental scales, but simulations are less reliable at the local scale. Some properties of climate are better captured by models than others; for example, temperature is generally more accurately simulated than rainfall.
Your ordinary reader, having read that disclaimer, will then be puzzled about the high confidence with which the writers then picture a future hotter, drier, more extreme Australia prone to droughts and floods. All in all, the whole Statement is a conflict between scientific caution and a global warming agenda.
The new version needs to recognise that despite these grim warnings, there has been no significant warming in the 21st century so far, that all the evidence points to warming having been good for the eco-system, plants, animals and humanity, that the models have been just woeful in accounting for temperature changes, and that sea-levels don’t seem to be rising in any untoward way. It would be really nice to read an account from the Academy which sets out the sheer unsettled state of the science.
But I don’t expect it. The Academy has been issuing dire warnings about climate for several years now, and will keep on doing so, avoiding answering the important questions. I do not imagine that the present Government will be a source of funding, however.