Global index proposed to avoid delays on climate policies

Professor David Frame, Director of Victoria's Climate Change Research Institute (CCRI), has co-authored a paper published today in the high profile international scientific journal Nature Climate Change. The paper argues that the 'pledge and review' approach that will form the basis of commitments made at the United Nations climate change negotiations in December, presents an opportunity to explicitly link mitigation goals to the evolving climate response.

The researchers, who have been collaborating at the Environmental Change Institute at the University of Oxford, say mitigation strategies need to be robust and better able to succeed despite the scientific, economic and political uncertainties. Learning from trial and error is an integral part of such an 'anti-fragile' strategy, as it allows for evolving knowledge to be incorporated at low costs.

The researchers recommend an adaptive strategy based on an index of warming attributable to human influence, drawn from observed temperatures. At the end of 2014, the rise in global mean temperature that can be attributed to the impact of people was calculated to be 0.91°C.

Such an index is not subject to high variability year to year, does not require complex modelling and could be updated annually, allowing governments to regularly review their pledges to reduce greenhouse gas emissions.

The paper concludes that using such an index allows a transparent link between the policy instrument and the policy goal. It says the index is a simple way to ensure consistency between changes in climate, individual countries' pledges, and the overall goal of reducing CO₂ emissions.

"The creation of an agreed index of global warming would be a useful tool to assist policymakers work out where we are in terms of achieving the main aims for climate policy," says Professor Frame. "As we know from inflation-targeting and other aspects of health, social and environmental policy, indexing can help governments by reducing the opportunity for diversionary arguments based on the selective use of data."

The paper also complements other work on adaptive management being done elsewhere within the CCRI, says Professor Frame. "Adaptive policies are attractive because they avoid the worst excesses of over-preparing in response to (very unlikely) worst-case scenarios, and the under-preparedness which often accompanies environmental planning based on cost-benefit approaches.

"At such a crucial time for climate negotiations, this proposed index offers a way to evaluate climate policies that tackles the uncertainty of climate response, which to date has stalled progress of mitigation strategies."