From months to Milankovitch: how timescale-dependent interactions in the coupled Earth system determine the spectrum of climate variability and response.*

Acting as both signal and noise, stochastic internal variability dominates the observational record of Earth's energy budget. While variability confounds estimates of anthropogenic climate change, it can also be leveraged for insight into the underlying physics, provided one understands both the governing stochastic processes, and the ways in which they are encoded in the statistics of observable quantities.

I will show how the frequency spectrum of Earth's temperature variability is determined by - and informs on - the climate system's radiative damping efficiency. This damping efficiency determines how much radiation the system sheds to space for a given change in surface temperature, and it is set by how the different components of the climate system - atmosphere, ocean, cryosphere, and the carbon cycle, interact across a range of timescales. The theoretical model for a timescale-dependent radiative damping efficiency is constrained by a combination of observations of broad-band variability drawn from both instrumental records as well as proxies of past climate change.