Without the ocean, the climate crisis would be even worse than it is. Every year, the ocean absorbs billions of tons of carbon from the atmosphere, preventing the warming that would otherwise be caused by greenhouse gases. Scientists have estimated that about 25 to 30 percent of all carbon emitted into the atmosphere by both humans and natural sources is absorbed by the ocean.
“But that number is a lot unclear,” said Ryan Woosley, a marine chemist and chief scientist at MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). Different parts of the ocean absorb different amounts of carbon, depending on many factors such as the season and the amount of storm mixing. Current carbon cycle models do not adequately reflect this difference.
To fill the gap, a team of Woosley and other MIT researchers has developed a research proposal for the MIT Climate Grand Challenges, an institute-wide campaign to encourage and fund innovative research to address the climate crisis. The team’s “Ocean Vital Signs” proposal includes sending a fleet of unmanned sailing aircraft to sail around the oceans and measure in detail how much carbon the ocean actually absorbs. Those data would be used to improve the accuracy of global carbon cycle models and to improve researchers ‘ability to verify countries’ positive emission reductions.
“If we start mitigation strategies – or by removing CO2 from the atmosphere or to reduce emissions – we need to know where CO2 “They’re going to find out how effective they are,” says Woosley. Without more accurate models, it is impossible to confirm whether the observed reduction in carbon dioxide is due to politics and humans, or to the ocean.
“So it’s a trillion-dollar question,” Woosley says. “If the countries spend all this money to reduce emissions, is that important enough?
In February, the team’s bid for the Climate Grand Challenges was announced as one of 27 finalists out of nearly 100 entries. From this list of finalists, MIT will announce in April a selection of five flagship projects for further funding and support.
Woosley leads the team along with Christopher Hill, chief research engineer at EAPS. The team consists of physical and chemical oceanographers, marine microbiologists, biogeochemists and computer modeling experts from across the department, as well as collaborators from the Media Lab and the Departments of Mathematics, Aeronautics and Astronautics, and Electrical Engineering and Informatics.
Today, data on the flow of carbon dioxide between the air and the oceans are collected in individual ways. Survey vessels depart from at intervals to collect data. Some commercial vessels are also equipped with sensors. However, they provide a limited view of the entire ocean and include bias. For example, commercial vessels generally avoid storms, which can increase the circulation of water exposed to the atmosphere and significantly increase the amount of carbon absorbed by the ocean.
“It’s very difficult for us to achieve and measure,” says Woosley. “But these drones can.”
If funded, the team project would begin by deploying several drones in a small area to test the technology. Wind-powered drones are made by a California-based company sailboat – navigate the territory independently, continuously collecting data on the flow of carbon dioxide in the air and sea with solar-powered sensors. It would then increase to more than 5,000 drone-day observations spread over five years and across all five ocean basins.
These data would be used to power neural networks to create more accurate maps of how much carbon the oceans absorb, reducing model uncertainty. These models would continue to be tested and refined with new data. “The better the models, the more we can rely on them,” says Woosley. “But we’ll always need measurements to check the models.”
Improved carbon cycle models are important not only for global warming. “CO2 it has a lot to do with how the world works, ”says Woosley. “We are made of carbon, all other organisms and ecosystems as well. What is the disruption of the carbon cycle doing to these ecosystems?
One of the best known effects is ocean acidification. The carbon absorbed by the ocean reacts to form acid. The more acidic ocean can have a devastating effect on marine organisms such as corals and oysters, whose calcium carbonate shells and skeletons can melt at lower pH. Since the Industrial Revolution, the ocean has become about 30 percent more acidic on average.
“It simply came to our notice then that the oceans were taking over CO2“It’s not great for the oceans,” says Woosley. “It’s also important to know how this uptake affects ocean health.
“Bacon fanatic. Social media enthusiast. Music practitioner. Internet scholar. Incurable travel advocate. Wannabe web junkie. Coffeeaholic. Alcohol fanatic.”