We investigate Earth-system processes that shape decarbonization strategy and timing. For example, many studies show that the global temperature response to carbon dioxide depends primarily on cumulative anthropogenic emissions over time (the basis of carbon budgets). We work to understand the mechanisms behind this behavior, identify when and why it may break down, and quantify the drivers of uncertainty in (for example) the zero-emissions commitment.

A rapid scale-up of renewables is essential to the energy transition, but wind, solar, and hydropower are inherently weather-dependent. We examine how to achieve a large-scale transition where energy and power systems remain reliable and affordable as variable renewables grow, examining the systematic challenges as well as opportunities posed by Earth system dynamics and its interactions with systemic risk.

We also work on fundamental problems in climate dynamics, including the nonlinear dynamics of monsoons. While long-term regional projections remain uncertain, key mechanistic questions are tractable: What processes stabilize monsoon regimes across a wide range of climatic conditions? How do regime stability, seasonal transition dynamics (onset and withdrawal), and subseasonal variability interact? Under what conditions might monsoon systems become fragile and undergo abrupt transitions?

Students in the group also study weather and climate variability and change across timescales. Key questions include: What controls the spatial pattern and overall strength of Earth-system feedbacks? How do feedbacks differ across forcing agents? And how are the resulting responses linked to large-scale shifts in the hydrological cycle?

An emerging theme is developing theory and methods for systematic ensemble design in Earth-system modeling: how to plan, interpret, and use ensembles across levels of model complexity to quantify (and where possible, reduce) uncertainty, while strengthening decision-making under deep uncertainty.