I am a PhD geoscience student at the University of Chicago, working with Dorian Abbot and Ray Pierrehumbert. I study the sensitivity of the Earth's climate to changes in the composition of the atmosphere, and how that sensitivity, and our estimates of it, can evolve over time. I use a range of approaches, including building simple mathematical models, running computer simulations that try to capture the full complexity of the Earth system, and analyzing observations of the Earth's recent past, as well as proxies of the climate of the distant past. I am co-organizer, with Maria Rugenstein, of the LongRunMIP project, which is an archive of millenial-scale runs of coupled general circulation models. I also was the head organizer of Rossbypalooza, a workshop bringing together climate scientists and statisticians for a week-long hackathon and lecture series.

Publications

Current research

• Bloch-Johnson, J., and D.S. Abbot. Nonlinear equilibrium climate sensitivity in a perturbed physics ensemble (in prep)
• Bloch-Johnson, J., D.S. Abbot, and M. Rugenstein. Spatial feedbacks from internal variability (in prep)
• Rugenstein, M., J. Bloch-Johnson., J. Gregory, T. Andrews, T. Mauritsen, C. Li, J.-L. Dufresne, G. Danabasoglu, A. Jonko, L. Cao, G. Schmidt, A. Abe-Ouchi, S. Yang, T. Frolicher, D. Paynter, and R. Knutti. Approaching equilibrium in climate models under elevated forcing (in prep)

Past research

• Abbot, D.S., J. Bloch-Johnson, J. Checlair, N. Farahat, R.J. Graham, D. Plotkin, P. Popovic, and F. Spaulding-Astudillo (2018). Decrease in hysteresis of planetary climate for planets with long solar days, The Astrophysical Journal
• Köhler, P., L.B. Stap, A.S. von der Heydt, B. de Boer, R.S.W. van de Wal, and J. Bloch-Johnson (2017). A state-dependent quantification of climate sensitivity based on paleodata of the last 2.1 million years, Paleoceanography, 32.
• Bloch-Johnson, J., R.T. Pierrehumbert, and D.S. Abbot (2015), Feedback temperature dependence determines the risk of high warming, Geophysical Research Letters. PDF, Supplementary Material.