A new study published on 24 September in Nature Climate Change has examined the country-level social costs of carbon (SSC). The commonly used metric of the expected economic damages from carbon dioxide (CO2) emissions is usually applied on a global scale. In this work, carried out by researchers from University of California San Diego, sought to determine differences in country-level contributions to the global SCC (GSCC) based on recent climate model projections, empirical climate-driven economic damage estimations, and socio-economic projections. According to the study, the US likely to be hit hardest, followed by India and Saudi Arabia.
The data set quantifying the social cost of carbon will be for each country was developed and the findings indicate that global estimates conceal the considerable differences in country-level SCCs (CSCCs). According to the results, “some of the world’s largest emitters also have the most to lose from their effects.” They found that countries which consistently have the largest contribution to the global cost are India, China, Saudi Arabia, and the US.
The global economic damage was also shown to be much higher than previous estimates. The new data suggest the GSCC is around $180–800 (€154–686) per ton of carbon emissions. This is much higher than one of the most trusted GSCC estimates ― that of the US Environmental Protection Agency (EPA) ― whose latest figures range from a mere $12–62 (€10–53) per metric ton of CO2 emitted by 2020. For the US alone, the new study estimated a CSSC of about $50 (€43) per ton. This represents a cost to the US economy of about $250 billion (€215 billion) per five billion metric tons of CO2, which is what the country emits each year.
Interestingly, the study suggests European Union countries, which have been the most active in addressing climate change, will be relatively unaffected, whereas countries that are less proactive are most economically affected by carbon emissions. They write, “Some countries, such as northern Europe and Canada, are leaders on climate policy despite potentially negative SCCs, whereas other countries with the highest CSCCs, like the United States and India, lag behind. The three highest-emitting countries (China, US, and India) have among the highest country-level economic impacts from CO2 emissions.
The authors suggest that “the high values and profound inequalities” highlighted by these estimates “provide a further warning of the perils of unilateral or fragmented climate action.” They also point to the fact that more “research is needed to estimate the geographical diversity of climate change impacts and to help devise policies.”
The findings have important implications, particularly since policymakers have often used previous claims that CO2 does not cause immediate harm to the economy in order to justify the loosening of regulations. For example, in addition to pulling out of the Paris climate pact, the Trump administration has scrapped a number of environmental regulations.
This is the first time researchers have reliably demonstrated the economic impact of CO2 emissions on individual countries. It is hoped that a better understanding of country-specific ramifications will provide incentivise for all nations to come together in an effort to mitigate climate change.
(1) Katharine Ricke, Laurent Drouet, Ken Caldeira, Massimo Tavoni. Country-level social cost of carbon. Nature Climate Change, 2018; DOI: 10.1038/s41558-018-0282-y