Will Burns, Ph.D., Co-Executive Director of the Institute for Carbon Removal Law and Policy at American University, delivered a lecture, titled “Antacids for the Sea: The Potential Role of Ocean Alkalinization Enhancement in Combating Climate Change,” that explored the potential role of the ocean in mitigating climate change, on Monday, Oct. 12.
The talk was held virtually, co-sponsored by the Monmouth University Institute for Global Understanding (IGU) and Urban Coast Institute (UCI) to launch their 2020 Global Ocean Governance Lecture Series.
“It’s really exciting to have Will here to help us kick off this series,” said Tony McDonald, Director of the UCI. “It’s an exciting time to think about the oceans; we hear about the problems like acidification and pollution. But I think we fail to fully appreciate the role oceans play in everything we do, oceans are the lungs of our planet, and incredibly important to our future.”
Burns began by reviewing the aim of the Paris Agreement: to keep the global temperature rise below two degrees Celsius. “However, if you look at the pledges, we are not on track for these temperatures and now project temperatures could rise from 3.2 to five degrees Celsius by the end of the century,” he said.
These temperatures could damage human institutions and ecosystems. A three to four degree increase in temperatures could cause the coral reefs that provide sustenance for a third of the ocean’s fish to disappear by the end of the century, endanger 60 percent of the world’s species, result in a reduction of crops, especially in the global south, and cause disease, Burns explained.
To mitigate these consequences, scientists have begun looking at ways to lessen carbon dioxide (CO2) levels after reaching predicted temperature thresholds through climate geoengineering, defined by the Oxford Geoengineering Program as the large-scale intervention in Earth’s natural systems to offset climate change.
A broad overview of approaches was presented, including solar radiation management, microbubbles, ocean iron fertilization, and ocean alkalinity enhancement. The solutions were largely theoretical, with some studied by way of localized field experiments. Each had benefits and risks associated with it, but the procedure of ocean alkalinity enhancement emerged as a more promising solution.
“Chemical weathering is a natural process that continuously erodes away rocks in our landscapes and sequesters [isolates] all the world’s carbon dioxide over the course of millions of years,” Burns said. “Enhanced ocean alkalinization is a process that’s intended to accelerate this by adding alkaline substances to seawater to enhance the ocean’s natural carbon sink.”
Basically, ocean alkalinity enhancement seeks to increase the ability of the world’s oceans to store CO2 and can be done in two ways.
First, adding alkalinity to the ocean, using silicate rich minerals like olivine, removes CO2 from the atmosphere through a series of reactions that converts and dissolves CO2 into stable bicarbonate and carbonate molecules, Burns explained. “This causes the ocean to absorb more carbon dioxide from the air to restore equilibrium.”
Another way to increase ocean alkalinity is to accelerate the weathering of limestone by dissolving limestone in a reactor with sea water of CO2 rich gases and reintroducing the water into the ocean, Burns suggested.
A beneficial byproduct of enhancing ocean alkalinization is that it might address ocean acidification occurring as a result of rising sea levels, but the extent to which it would occur is uncertain, Burns added.
Similarly, studies differ on how much sequestration of CO2 would occur using this solution. “They have different methodologies, assumptions of the scales at which we might be able to deploy this, and as a consequence, conclusions vary widely,” Burns clarified. “One study found we could draw down CO2 by 30 parts per million and others have indicated that by 2100 we could reduce levels by 160 to 450 parts per million.”
On top of lacking concrete results, ocean alkalinization enhancement might disadvantage organisms that couldn’t process the alkalinity and it could cause spontaneous precipitation of calcium hydroxide, damaging coral reefs and contaminating food by releasing minerals like nickel and iron, Burns assessed.
For years, solutions were focused on carbon capture used for energy and de-forestation and reforestation, but they are thought to be unsustainable large-scale. These issues have led scientists to consider the potential role oceans play in climate geoengineering.
Randal Abate, Director of the IGU and professor of political science, described Burns as having the “expertise perfectly situated to kick off the series.”
Burns is regarded as a national and global expert in climate geoengineering, pursuing cutting-edge initiatives, explained Abate. Burns’s research agenda includes climate geoengineering, climate damage, and the effectiveness of the European Union Emissions Trading System.
PHOTO COURTESY of Monmouth University