Without the ocean, the climate crisis would be even worse than it is. Each year, the ocean absorbs billions of tons of carbon from the atmosphere, preventing warming that greenhouse gas would otherwise cause. Scientists estimate about 25–30% of all carbon released into the atmosphere by both human and natural sources is absorbed by the ocean.
“But there’s a lot of uncertainty in that number,” said Ryan Woosley, a marine chemist and a principal research scientist in the Department of Earth, Atmospheric, and Planetary Sciences (EAPS) at the Massachusetts Institute of Technology (MIT). Different parts of the ocean take in different amounts of carbon, depending on many factors, such as the season and the amount of mixing from storms. Current models of the carbon cycle don’t adequately capture this variation.
To close the gap, Woosley and a team of other MIT scientists developed a research proposal for the MIT Climate Grand Challenges competition—an institutewide campaign to catalyze and fund innovative research addressing the climate crisis. The team's proposal, Ocean Vital Signs, involves sending a fleet of sailing drones to cruise the oceans taking detailed measurements of how much carbon the ocean is really absorbing. Those data would be used to improve the precision of global carbon cycle models and improve researchers’ ability to verify emissions reductions claimed by countries.
“If we start to enact mitigation strategies—either through removing CO2 from the atmosphere or reducing emissions—we need to know where CO2 is going in order to know how effective they are,” Woosley said. Without more precise models, there’s no way to confirm whether observed carbon reductions were thanks to policy and people or thanks to the ocean.
“So that’s the trillion-dollar question,” Woosley said. “If countries are spending all this money to reduce emissions, is it enough to matter?”