Fixed climate feedback assumptions systematically underestimate policy-relevant economic risks: Implications for climate resilience

TY - JOUR

T1 - Fixed climate feedback assumptions systematically underestimate policy-relevant economic risks

T2 - Implications for climate resilience

AU - Shen, Wen Qi

AU - Xu, Jian Jun

AU - Tu, Shi Fei

AU - Cao, Ning

AU - Liao, Hua

AU - Yuan, Xiao Chen

AU - Wei, Yi Ming

N1 - Publisher Copyright: © 2026 The Authors

PY - 2026/8

Y1 - 2026/8

N2 - Integrated Assessment Models (IAMs), central to informing climate policy, typically treat the climate feedback parameter as a fixed constant, contradicting robust evidence that it weakens as the planet warms. Here, we show that this structural simplification systematically underestimates policy-relevant economic risks. By integrating a state-dependent feedback mechanism calibrated to CMIP6 Earth System Models into a coupled DICE-FaIR framework, we reveal three key findings. First, dynamic feedback produces a consistent warming amplification of ∼0.2 °C across policy scenarios, demonstrating that conventional IAMs physically underestimate future warming trajectories. Second, this physical bias cascades into economic metrics, elevating the Social Cost of Carbon by up to 50% across diverse structural specifications, indicating a systematic limitation rather than a parameter-specific outcome. Third, we identify a ‘policy space compression’ effect: dynamic feedback simultaneously amplifies the tail risks of exceeding critical temperature thresholds while narrowing the feasible window for net-zero emissions. This physically driven compression is systematically obscured by fixed-feedback assumptions, which overstate the available policy space and understate the urgency of accelerating mitigation timelines. These findings demonstrate that neglecting the temperature-dependent weakening of climate feedback creates a biased foundation for risk assessment, with current resilience strategies potentially calibrated to overly optimistic baselines that inadequately account for the evolving dynamics of the Earth system.

AB - Integrated Assessment Models (IAMs), central to informing climate policy, typically treat the climate feedback parameter as a fixed constant, contradicting robust evidence that it weakens as the planet warms. Here, we show that this structural simplification systematically underestimates policy-relevant economic risks. By integrating a state-dependent feedback mechanism calibrated to CMIP6 Earth System Models into a coupled DICE-FaIR framework, we reveal three key findings. First, dynamic feedback produces a consistent warming amplification of ∼0.2 °C across policy scenarios, demonstrating that conventional IAMs physically underestimate future warming trajectories. Second, this physical bias cascades into economic metrics, elevating the Social Cost of Carbon by up to 50% across diverse structural specifications, indicating a systematic limitation rather than a parameter-specific outcome. Third, we identify a ‘policy space compression’ effect: dynamic feedback simultaneously amplifies the tail risks of exceeding critical temperature thresholds while narrowing the feasible window for net-zero emissions. This physically driven compression is systematically obscured by fixed-feedback assumptions, which overstate the available policy space and understate the urgency of accelerating mitigation timelines. These findings demonstrate that neglecting the temperature-dependent weakening of climate feedback creates a biased foundation for risk assessment, with current resilience strategies potentially calibrated to overly optimistic baselines that inadequately account for the evolving dynamics of the Earth system.

KW - Climate resilience

KW - Climate risk

KW - Dynamic climate feedback

KW - Economic risk assessment

KW - Integrated assessment model

UR - https://www.scopus.com/pages/publications/105037829505

U2 - 10.1016/j.accre.2026.04.004

DO - 10.1016/j.accre.2026.04.004

M3 - Article

AN - SCOPUS:105037829505

SN - 1674-9278

VL - 17

SP - 890

EP - 901

JO - Advances in Climate Change Research

JF - Advances in Climate Change Research

IS - 4

ER -