Existing climate models underestimate climate change risks and the potential of technology to combat it, climate change economist Nick Stern said.
In an article published in the journal Nature, Stern called on researchers to radically improve the models used to estimate the costs of tackling climate change.
He said the existing integrated assessment models (IAMs) struggle to incorporate the scale of scientific risks, as they do not account for tipping points and catastrophic changes, such as thawing of permafrost and release of methane into the atmosphere. Neither do they account for some of the largest potential impacts of climate change, such as extreme weather and conflict.
‘It is these hard-to-predict impacts that are the most troubling potential consequences of inaction,’ Stern said.
A more robust body of economics literature was required to inform the Intergovernmental Panel on Climate Change (IPCC), said Stern, who called on scientists and engineers to assist economists to devise models.
Current models of the economic impacts of reducing greenhouse gas emissions can mislead policymakers, Stern wrote.
The business-as-usual baseline, against which costs of action are measured, includes an alternative option in which fossil fuels are consumed in ever greater quantities without any negatives consequences to growth itself, the article states.
New types of modelling recommended by Stern include agent-based models (ABMs), which are widely used in the finance sector and could help understand complex changes to the economy under climate change.
‘The IPCC should distil what policymakers need to inform their decision-making. Learned societies and national academies must bring together researchers from a wide range of relevant disciplines to focus attention on improving economic modelling quickly,’ he wrote.
The article concludes: ‘There is huge potential in future technologies that can drive change. These are omitted or badly underestimated in current climate modelling — deeply damaging to our guidance for policymaking.’
IPCC reports have been criticised in the past for being incomprehensible to non-experts, hampering the efforts of policymakers to act on climate change. The organisation met in Norway in early February to develop recommendations for making IPCC reports more readable, accessible and policy-relevant.
‘IPCC assessments are recognised as the definitive source of scientific information on climate change; our challenge is to ensure that non-specialists can follow them and that policymakers and other users can find and use what is relevant to them,’ said IPCC Chair Hoesung Lee.
