September 14, 2023 | Nature Climate Change |
A study conducted by Tsinghua University in China presents updated estimates of the social cost of greenhouse gases (SC-GHGs), a critical metric for informing climate policies. The study focuses on methane (SC-CH4) and nitrous oxide (SC-N2O) emissions, providing fresh insights by incorporating the latest scientific findings in damage functions, climate models, and socioeconomic projections.
The research utilizes a multimodel assessment framework to re-evaluate SC-CH4 and SC-N2O. Notably, the study highlights the effects of emissions on gross domestic product (GDP) levels, revealing a SC-CH4 of US$2,900 per ton of methane and a SC-N2O of US$49,600 per ton of nitrous oxide for the year 2020. These figures represent a substantial twofold increase compared to previous estimates.
However, the study doesn't stop there. It also considers the impact of GDP growth over time, which leads to a staggering 15–25-fold increase in these estimates. This temporal factor significantly dominates the uncertainty in social cost calculations.
While uncertainties still persist, the findings strongly advocate for more immediate and robust policies aimed at mitigating CH4 and N2O emissions. In essence, the study underlines the urgency of addressing these potent greenhouse gases and implies that their mitigation can yield greater benefits than previously recognized in climate policy discussions.
Read more: Damage function uncertainty increases the social cost of methane and nitrous oxide
Fig. | SC-CH4 and SC-N2O estimates for the emissions year 2020 and global climate damage obtained with various damage models, with Hector as are presentative climate model. g,h, Percentage loss in global GDP due to climate change by the level-based damage models (g) and growth-based damage models (h); coloured lines show the simple mean values and the coloured uncertainty bands show the 5th to 95th range of changes in global GDP.