Changes in climate variability are as important for society to address as are changes in mean climate (Rehfeld et al, 2018). This project would look at how climate variability (such as El Nino) depends on the climate itself. It will use a suite of model simulations, which are being developed for the upcoming IPCC report. Observations shows a strong reduction in variability since the last glacial (Rehfeld et al, 2018), and a reduction in the Atlantic Meridional Overturning Circulation in the past 200 (Thornalley et al, 2018). How does this compare to the behvaiour of state of the art Earth System Models? Their future scenarios will provide insight into how variability might alter going forward. The impacts of these changes will be determined with PAGE20, a new version of the physical-socioeconomic model used in the influential Stern Review into the Economics of Climate Change.