News release

From: Springer Nature

Economics: The costs of climate change

Future economic costs associated with historical carbon dioxide (CO₂) emissions may be at least 10 times higher than costs already incurred from the same emissions, a study in Nature suggests. The work provides a measure of losses and damages that could be used to quantify the debts caused by CO₂ emitters.

Climate change has measurable negative effects on humans, often with populations experiencing the most harm being responsible for only a small fraction of historical emissions. These effects have motivated political and legal efforts that seek to link these damages to specific emissions. However, there has been a lack of clarity on how exactly to define these losses and damages for which neither climate mitigation nor adaptation is a solution.

Marshall Burke and colleagues provide a quantitative framework to link individual emissions to global and local-level damages, based on an estimation of how warming temperatures are linked to economic output (mostly based on GDP) and a suite of climate models that translate changes in emissions to changes in warming. The resulting estimated losses and damages from CO₂ emissions can be computed from three components: the historical damages that have already occurred due to past CO₂; the future damages expected to occur from these past emissions; and the future damages expected to occur from present or future emissions. The authors estimate that 1 tonne of CO₂ emitted in 1990 caused US$180 in cumulative global damages by 2020 but will cause an additional $1,840 worth of damage by 2100. Looking at examples of damages caused by specific emitters in different regions, US emissions since 1990 are estimated to have caused $10 trillion in damages around the world, including $500 billion of damage in India and $330 billion in Brazil. Emissions from European countries over that period are estimated to have caused more than $6 trillion in global damages. They also calculate that a single long-haul flight per year over the past decade leads to about $25,000 in future damages by 2100.

Calculated damages do not necessarily indicate what is ‘owed’ to affected regions by the CO₂ emitters, the authors note, as compensation is a moral and legal question. However, defining the losses and damages associated with climate change could be used to direct efforts to limit future damages, including in efforts to hold emitters accountable for the damages from their emissions. Although carbon removal strategies may have potential to reduce such debts, the study suggests they only work well when used at the time of emission.