The IPCC truth: flawed, but don’t believe everything you read
Reading some of the media coverage on the report into the Intergovernmental Panel on Climate Change, you'd think it had condemned the IPCC for gross misrepresentation of the climate science. Climate scientist Andrew Macintosh cuts to the truth.
Reading some of the media coverage on the Netherlands Environmental Assessment Agency’s report on the Intergovernmental Panel on Climate Change (IPCC), you’d think it had condemned the IPCC for gross misrepresentation of the climate science. The Australian, for example, went with the headline ‘UN’s climate report one-sided’. While this may fit the worldview of some Oz readers, it does not reflect the content of the report.
The investigation was triggered by the revelation the IPCC’s report on the impacts of climate change (known as the Working Group II report) contained errors about the expected rate of melting of the Himalayan glaciers and the proportion of land in the Netherlands that is below sea level. These errors were reported widely and fed scepticism about the integrity of the IPCC and climate change science more broadly.
In response, the Netherlands Environmental Assessment Agency was asked to evaluate the veracity of the conclusions on regional impacts in the Working Group II report. It was a perfect fit to perform this task as it has an exceptional reputation and contains some of the world’s leading climate researchers and analysts.
Far from condemning the IPCC for unforgivable incompetence or bias, the agency essentially found the report accurately represented the current state of the impact science. In its words:
“Overall the summary conclusions are considered well founded and none were found to contain any significant errors. The Working Group II contribution to the Fourth Assessment Report shows ample observational evidence of regional climate change impacts, which have been projected to pose substantial risks to most parts of the world, under increasing temperatures.”
Having said that, the report did note several shortcomings. The one that has been leapt on by conservative media outlets is that the summary report tended to focus on the negative impacts of climate change and highlight worst-case scenarios, while downplaying or ignoring potential positive impacts. According to the agency, this was not a product of a desire on behalf of the IPCC authors to deceive or push a particular perspective. Rather, the authors had sought to highlight the findings they thought were most relevant to policy makers.
Climate policy is about managing risk and uncertainty. Of particular importance are “high-impact, low probability” events; where there is a small chance of very bad outcomes. Given this, there is logic to adopting what the Netherlands Environmental Assessment Agency called a “risk-orientated” approach in assessing climate impacts. This is similar to what governments and other policy analysts do when evaluating defence, security and health risks.
The agency’s conclusion on this point was that “it is appropriate — and even necessary — to apply a risk-oriented approach to climate-change impact assessment”. But it stated Working Group II should include more information on the approach it adopts to the presentation of information and the positive impacts of climate change so as to avoid misunderstandings and ensure policy makers are fully informed of the range of potential outcomes.
The other significant findings from the review were that: (a) in two out of 32 conclusions that were studied, generalisations were made that were not sufficiently founded on the current science; and (b) a small number of errors and inaccuracies were identified, most of which were of little consequence. Overall, the agency found that their:
“…findings do not contradict the main conclusions of the IPCC on impacts, adaptation and vulnerability related to climate change. There is ample observational evidence of natural systems being influenced by climate change on regional levels. The negative impacts under unmitigated climate change in the future pose substantial risks to most parts of the world, with risks increasing at higher global average temperatures.”
So while some commentators and media outlets will have you believe the IPCC has been discredited, the truth is different.
The report does not challenge the IPCC’s position as the preeminent store of knowledge on the state of climate science. Of course, IPCC processes are not perfect; they cannot be and few claim they are. More resources need to be devoted to peer review and quality control, and the summary reports need to provide a more complete picture of the science — if only to avoid the perception of bias.