The BBVA Foundation Frontiers of Knowledge Award in Climate Change goes, in this ninth edition, to Syukuro Manabe and James E. Hansen for their foundational contributions to the development of mathematical models of the climate system, and their pioneering use of these models to understand and project how Earth’s climate responds to changing concentrations of atmospheric CO2 and other perturbations. Their seminal contributions underlie the modeling and analysis frameworks in use today.
In the 1960s, Manabe developed physicsbased mathematical models describing the interplay between radiative and convective energy flows, and their interaction with other components of the climate system. These models allowed him to quantify the effect of atmospheric composition and solar perturbations on global temperature. In the mid-1970s Hansen, who had been studying planetary atmospheres, adapted similar models to begin studying Earth’s climate. Calculations by both researchers formed the basis for the first assessment of the sensitivity of Earth’s equilibrium surface temperature response to a doubling of atmospheric CO2. Hansen built upon these approaches to project how surface temperatures would evolve in response to time varying perturbations. His projections, including one on when warming by CO2 would leave the envelope of natural variability, have stood the test of time.
Through painstaking critical analyses, Hansen and Manabe quantified factors controlling the magnitude of the surface temperature response to external perturbations. The analysis methods they developed have become central to identifying the primary sources of remaining uncertainty in predictions of future climate change.