Artificially stimulating phytoplankton can lower carbon dioxide levels and combat climate change

The main conversation about climate change focuses mainly on one thing: how much carbon is in the air – and thus, how to reduce it. However, what is less talked about but could become very important is the amount of carbon in our oceans. there 50 times More carbon is in the ocean than in the atmosphere. Some climate researchers believe that if we could slightly increase the amount of carbon the oceans could absorb from the atmosphere, we could avoid some of the worst effects of climate change.

This may sound unusual when you first hear it, but think about it a little longer. Almost covers the ocean 70 percent From the Earth’s surface, it naturally absorbs carbon dioxide – effectively dissolving it. Phytoplankton In the ocean, it used carbon dioxide and sunlight to carry out photosynthesis just like terrestrial plants. Oxygen is produced through this process – phytoplankton are actually responsible for about 50 percent of oxygen in our atmosphere.

Some climate researchers have suggested that if we could increase the amount of phytoplankton in the ocean, we could pull more carbon from the atmosphere. The well-known method of producing phytoplankton blooms is to introduce them iron, an important nutrient for the plankton community, for water. Many parts of the ocean low in ironso even a relatively small addition of iron could theoretically produce a lot of phytoplankton and thus remove a lot of carbon dioxide from the atmosphere.

“Give me an iron half tanker, and I’ll give you an ice age,” John Martin, oceanographer at Moss Landing Marine Laboratories, Wrote in 1988. At that time, most people were just beginning to recognize the idea of ​​climate change as we know it now. But that’s also at a time when people are beginning to think about how iron enrichment can affect phytoplankton growth, thus altering carbon levels in the atmosphere.

Although climate scientists have spent a significant amount of time discussing this strategy among themselves, there has been no concerted effort to explore it further and take it seriously. Ken Busseler, a marine radiochemist at Woods Hole Oceanographic Institution, a scientist who did some research in iron enrichment in the ocean. He and his team looked at whether introducing iron could “alter the flow of carbon into the deep ocean” and found that there was an important carbon sequestration effect.

His research was conducted nearly 20 years ago, Buessseler told The Daily Beast, and there hasn’t been much since then.

“What happened 20 years ago is that we started spinning and spreading a chemical form of iron and looking for phytoplankton — the plant response — and it really showed very clearly that if you improve iron, you can create more uptake from carbon dioxide,” Busseler said. “The difference between now and 20 years ago is that I think the climate crisis is more visible to the public.”

NASA

Using the oceans to combat climate change has become a much discussed topic among climate scientists in recent years, and Buesseler was part of the group of scientists that released a report by the National Academies of Sciences, Engineering, and Medicine late last year that looked at options, including increasing levels of phytoplankton.

“We have a big reservoir. It already takes up a third of greenhouse gases. The question people are asking the most now is what can we do to boost that?” Buesseler said. “Let’s get out there. Let’s do experiments.”

The experiments themselves won’t cause any harm to the ocean’s natural ecosystem, Buesseler said, but they could tell us a lot about how bringing more iron into the ocean on a much larger scale will affect this ecosystem in the long run. He doesn’t think doing it on a large scale would cause much harm, but it’s important to do the research so we can find out for sure. He said the “very conservative” estimate is that up to gigatons of carbon dioxide could be sequestered each year if the process were carried out on a large scale.

“It will change the types of plants and animals that grow, but that’s already happening with changes in temperature and acidity,” Busseler said.

Enriching with iron would also be very easy, David Siegel, professor of marine sciences at the University of California, Santa Barbara, told The Daily Beast. You can simply get a 120ft fishing boat and start spreading the iron as it will be most effective for stimulating the growth of phytoplankton.

This can be done relatively inexpensively. Every atom of iron you add in the right places can make tens of thousands of carbon atoms immobile, meaning water absorbs them. “It’s fairly effective,” Siegel said. “You can spread pots that release iron oxide into the water – even just iron ore in the water – and you can make flowers that you can see from space. We know that.”

The effects will happen fairly quickly. Scientists who have introduced iron into seawater in the past have noticed that phytoplankton blooms can begin to appear within the first 24 hours. The ideal place to introduce iron would be places that are less abundant, which would be parts of the ocean – primarily in the Southern Hemisphere – not close to Earth. Usually comes the iron that ends up in the ocean of dust that blows into the ocean from the land.

Buesseler and Siegel stressed that this should not be viewed as a substitute for ending the use of fossil fuels. This is still critical when it comes to having a chance to beat climate change. But avoiding the worst effects of climate change will also require developing decarbonization strategies to reduce the burden of greenhouse gases in the air.

“Even if we remove carbon from our economies, there is still 20 gigatons or so of carbon dioxide that must be removed from the atmosphere to keep us anywhere near the Paris Agreement targets,” Siegel said.