Nikki Lovenduski

Since the beginning of the industrial revolution, anthropogenic emissions of carbon dioxide (CO₂) have increased exponentially, driving increases in global atmospheric temperature. Only about half of the CO₂ emitted from anthropogenic activities has remained in the atmosphere; the other half has been taken up by natural carbon sinks: the ocean and the terrestrial biosphere. The global ocean has absorbed ~35% of the CO₂ released by human activities since 1765. In the absence of this oceanic CO₂ uptake, atmospheric CO₂ concentrations would likely be much higher, and atmospheric temperatures would likely be warmer. Quantifying and understanding the uptake of CO₂ by the ocean is a necessary step for making accurate predictions of future climate change.

My research aims to improve our understanding of the ocean’s role in the global carbon cycle by investigating the physical, chemical, and biological processes controlling air-sea CO₂ exchange. I study how these processes operated in the past, how they function today, and how they might respond to anthropogenic climate change in the future. To do this, I employ a hierarchy of ocean and Earth system models along with satellite and in situ observations.

The major focus of my research thus far has been the exchange of CO₂ between the atmosphere and the Southern Ocean, a large oceanic region stretching from the Antarctic continent to the subtropics of the Southern Hemisphere. The Southern Ocean is a region of critical importance to the global carbon cycle, as it is responsible for approximately half of the oceanic CO₂ uptake. My research has helped to show that the absorption of CO₂ by the Southern Ocean may have slowed in recent decades, due to anthropogenic changes in the climate system.