Siddharth’s research lies at the core of the CVU’s interdisciplinary approach. He brings together astronomy and climate science to better understand both Earth’s climate and the climates of exoplanets. A central focus of his work is climate multistability, the idea that a planet subject to the same external forcing can sustain markedly different stable climate states, such as a snowball state, a temperate climate, or a runaway “steam” atmosphere.

To investigate this phenomenon, Siddharth employs a hierarchy of models, ranging from a one-dimensional Energy Balance Models (EBMs) he developed, to a three-dimensional Global Climate Model (3D GCM) he improved. He is particularly interested in the role of ocean heat transport in shaping multistable regimes and in determining the climate states accessible to exoplanets. In this context, he has enhanced the ocean component of the Generic-PCM (the GCM we use) to more realistically represent oceanic transport processes.