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 -