Abstract Polar amplification is a robust feature of greenhouse‐gas‐forced climate change. Previous studies have typically examined it over a fixed time period or following an abrupt increase in atmospheric . Here, we investigate how the transient evolution of polar amplification depends on the rate of atmospheric increase up to a fixed concentration using a global climate model. We find that Arctic amplification is initially strong but subsequently suppressed for several centuries when atmospheric increases rapidly ( ), due to changes in ocean circulation, associated heat transport, and amplifying radiative feedbacks. In contrast, Antarctic amplification emerges gradually across all ramping‐rate experiments but exhibits an abrupt increase more than 1,000 years after atmospheric stabilizes, triggered by a Ross Sea convective event that transports deep ocean heat to the surface. These findings demonstrate that the rate of forcing strongly shapes how both the magnitude and mechanisms of polar amplification evolve over time.
Hankel et al. (Sun,) studied this question.