Abstract Overshoot scenarios are frequently presented as flexible paths to climate goals, premised on the assumption that harms incurred during overshoot can be undone. Yet the conditions under which economic damages are actually reversible remain poorly understood. Here we explore the consequences of overshoot, systematically examining the physical and economic uncertainties that shape the extent and reversibility of economic damages. Taking these uncertainties into account, each additional 0.1°C of warming by 2030 locks in 1.7 to 12 percentage points of end-of-century global GDP losses under a current policies pathway, reflecting a robust relationship between near-term warming and long-term economic outcomes. In high-sensitivity cases with persistent growth damages, over 30% of countries face risks of absolute declines in GDP per capita within this century. We find that economic damages may be irreversible over the 21st century even under scenarios where global temperatures decline before 2100. A temporary overshoot of about 0.2°C may result in GDP losses about 14% to 31% higher than for a no overshoot case. With vulnerable countries being most affected, overshoot is projected to increase global inequality. Our findings underscore the economic risks of climate overshoot and the need for stringent near-term emission reductions to limit climate risks.
Schoengart et al. (Wed,) studied this question.