Carl Wunsch, Frontiers of Knowledge Award for Revealing the Impact of Global Warming on Oceans

Guided by this idea, Wunsch developed innovative methods to precisely quantify the state of the ocean under a changing climate and demonstrated the need for a global ocean observing system capable of integrating data obtained from space or from inside the ocean. His work has been instrumental in the design of ongoing global ocean observation programs, the committee added, which make it possible to estimate the increase in ocean temperatures in response to increasing greenhouse gases.

“Before Professor Wunsch’s work, there wasn’t any kind of coherent global ocean observation system,” explained committee secretary Carlos Duarte, who underscored that these advances have enabled the measurement of phenomena such as sea level rise, ice melt in polar oceans and increases in the ocean’s heat content, which is driving the intensification of extreme weather events.

A ‘radically different’ strategy for studying the ocean

Carl Wunsch initially studied mathematics at MIT, but before long he steered his career toward oceanography, drawn by the influence of Henry Stommel and the fieldwork at sea. However, the limitations of traditional measurements, which were expensive and slow, exposed the need to transform the scientific approach in the field.

In the 1970s, technological advances began to reveal a dynamic, complex ocean. It was then that Wunsch discovered “a serious observational problem” that made it impossible to understand its evolution in the context of climate change.  His participation in a 1979 pioneering study on the impact of CO₂ demonstrated a lack of reliable data to address essential questions regarding the ocean’s role in the climate system.

In response to this gap, he spearheaded a profound methodological change: developing global observation systems and analytical tools capable of measuring the oceans’ temperatures and thermal energy on a global scale.

Pioneering missions and global observation

Some of his most notable contributions include his role in launching the World Ocean Circulation Experiment (WOCE) in 1990, conceived to offer a comprehensive global overview of heat flux linked to ocean circulation. This project, which used satellite readings and marine sensors for over a decade, laid the groundwork for our current understanding of ocean behavior.

He later played a leading role in developing the high-precision altimeter, which culminated in 1992 with the TOPEX/Poseidon project. It enabled the continuous measurement of the dynamic topography of the ocean surface from space and the calculation of changes in the ocean’s heat content. These innovations opened the door to unprecedented, continuous global observation.

Starting in 1998, Wunsch’s vision took shape in the Argo project, an international network of thousands of free-floating buoys that systematically monitor ocean temperature, salinity and currents down to a depth of 2,000 meters – critical data to study climate change.

Rising risks and international cooperation

The observations gathered over decades clearly show that global sea levels are rising and that heat is accumulating in the oceans, increasing the probability of extreme weather events like heat waves, heavy rain and flooding. “The more energetic the ocean is, the more extreme events you can expect,” Wunsch warned.

Given this scenario, the researcher stresses the importance of global scientific cooperation, a principle he has championed throughout his career. As the committee noted, his contributions reveal that it is only possible to understand the evolution of the climate system and face its consequences for the planet through global collaboration.