Events

 
Online Seminar

The state-dependence of climate sensitivity: a paleoclimate perspective

Tuesday, 12 November 2019, 14:00-15:00
University of Leeds

Climate sensitivity is a key metric used to assess the magnitude of global warming given increased CO2 concentrations. The geological past can provide insights into climate sensitivity, and this talk will begin with a review of some previous studies that have attempted to constrain climate sensitivity with paleo data and models.  However,on timescales of millions of years, factors other than CO2 can drive climate, including paleogeographic forcing and solar luminosity. Here, through an ensemble of climate model simulations covering the period 150–35 million years ago, we show that climate sensitivity to CO2 doubling varies between ∼3.5 and 5.5 ◦C through this time. These variations can be explained as a nonlinear response to solar luminosity, evolving surface albedo due to changes in ocean area, and changes in ocean circulation. The work shows that the modern climate sensitivity is relatively low in the context of the geological record, as a result of relatively weak feedbacks due to a relatively low CO2 baseline, and the presence of ice and relatively small ocean area in the modern continental configuration.

 

This event is part of the eventgroup ICAS External Seminar
Speaker
Dan Lunt

University of Bristol
Organizer
School of Earth & Environment
University of Leeds
Leeds
Mail: M VanDerGucht does-not-exist.leeds ac uk
Targetgroup
Scientific Staff
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