Enhanced global carbon cycle sensitivity to tropical temperature linked to internal climate variability.

ABSTRACT: The sensitivity of atmospheric CO₂ growth rate to tropical temperature (γ^T) has almost doubled between 1959 and 2011, a trend that has been linked to increasing drought in the tropics. However, γ^T has declined since then. Understanding whether these variations in γ^T reflect forced changes or internal climate variability in the carbon cycle is crucial for future climate projections. We show that doubling sensitivity events can arise in simulations by Earth system models with perturbed initial conditions but are likely explained by internal climate variability. We show that the doubling sensitivity event is associated with the occurrence of a few, but very strong, El Niño events, such as 1982/83 and 1997/98. Such extreme events result in concurrent

SUBMITTER: Li N 

PROVIDER: S-EPMC11423872 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature