Large potential reduction in economic damages under UN mitigation targets
International climate change agreements typically specify global warming thresholds as policy targets, but the relative economic benefits of achieving these temperature targets remain poorly understood. Uncertainties include the spatial pattern of temperature change, how global and regional economic output will respond to these changes in temperature, and the willingness of societies to trade present for future consumption. Here we combine historical evidence with national-level climate and socioeconomic projections to quantify the economic damages associated with the United Nations (UN) targets of 1.5 °C and 2 °C global warming, and those associated with current UN national-level mitigation commitments (which together approach 3 °C warming).
Despite the Paris Agreement’s focus on the 1.5 °C and 2 °C targets, its actual Nationally Determined Contributions (NDCs) are instead consistent with 2.5–3 °C of global warming. We estimate that this level of warming could lead to a reduction in global GDP as high as 10% by mid-century and 15%–25% by the end of the century…