Major conversations about climate change have focused primarily on one thing: how much carbon is in the air – and, by extension, how to reduce it. However, what is less talked about, but may be very important, is the amount of carbon in our oceans. The ocean contains 50 times more carbon than the atmosphere. Some climate researchers believe that if we can slightly increase the amount of carbon that the oceans can absorb from the atmosphere, we could avoid some of the worst effects of climate change.
It might sound unusual when you first hear it, but think about it a little more. The oceans, covering about 70 percent of Earth’s surface, naturally absorb carbon dioxide – effectively dissolving it. Phytoplankton in the ocean, it uses carbon dioxide and sunlight to perform photosynthesis like land plants. Oxygen is produced through this process – phytoplankton are actually responsible for about 50 percent of the oxygen in our atmosphere.
Some climate researchers have suggested that if we can increase the amount of phytoplankton in the oceans, we can take more carbon out of the atmosphere. One well-known way that phytoplankton bloom is by introducing iron, an essential nutrient to the plankton community, into the water. Iron content is low in many parts of the ocean, so 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.
John Martin, an oceanographer at Moss Landing Marine Laboratories, wrote in 1988, “Give me a half-iron tanker, and I’ll give you an ice age.” At the time, most people were new to the idea of climate. Change as we know it today. But it was also at a time when people began to think about how iron enrichment might affect the growth of phytoplankton, changing the level of carbon in the atmosphere.
Although climate scientists have spent a lot of time discussing this strategy among themselves, no concerted effort has been made to explore it further and take it seriously. Ken Bussler, a marine radiochemist at the Woods Hole Oceanographic Institute, a scientist who conducts several studies on iron enrichment in the ocean. He and his team looked to see whether the introduction of iron “could alter the flow of carbon into the deep ocean” and found that there was a significant carbon sequestration effect.
Bussler told The Daily Beast that his research was done about 20 years ago, and not much has been done since.
“What happened 20 years ago was that we started to spin and propagate the chemical form of iron and look for phytoplankton – the plant response – and it actually showed very clearly that if you increase the iron , then you can increase more carbon dioxide,” Bussler said. “The difference between now and 20 years ago is that I think the climate crisis is more visible to the public.”
Using the oceans to tackle climate change has become a hotly debated topic among climate scientists in recent years, and Buessler was part of a group of scientists that led the National Association for Science, Engineering and Medicine late last year. A report was released by the academies looking at the options. , including increasing levels of phytoplankton.
“We have a big reservoir. It already consumes a third of greenhouse gases. The same question most people ask today is, what can we do to fix this?” Bussler said. “Let’s go outside. Let’s experiment.”
Bussler said the experiments themselves will not harm the ocean’s natural ecosystems, but they can tell us a lot about how excess iron in the ocean on a large scale will affect these ecosystems in the long term. He doesn’t think doing it on a large scale will do much harm, but it’s important to do some research so we can find out for sure. He said a “very conservative” estimate was that up to gigatonnes of carbon dioxide could be absorbed annually if the process was carried out on a large scale.
,The difference between now and 20 years ago is I think the climate crisis is more visible to the public.,
, Ken Bussler, Woods Hole Institute of Oceanography
“It will change the type of plants and animals that grow, but it actually happens with changes in temperature and acidity,” Bassler said.
Iron enrichment is also easy, David Siegel, a professor of marine science at the University of California, Santa Barbara, told The Daily Beast. You can simply get a 120 foot fishing boat and start spreading the iron as it will be most effective in stimulating the growth of phytoplankton.
This can be done relatively inexpensively. Every iron atom you add in the right place can immobilize tens of thousands of carbon atoms, meaning the water absorbs them. “Quite effective,” said Siegel. “You can scatter pots that release iron oxide into the water — even iron ore in the water — and you can make flowers that you can see from space. We know that.”
The effect will happen quite quickly. Scientists who have added iron to seawater in the past have suggested that phytoplankton blooms may have started within the first 24 hours. The ideal place for iron to enter is less abundant places, which would be part of the oceans – especially in the Southern Hemisphere – not close to Earth. It seems generally that iron gets absorbed into the oceans by dust blowing from land to sea.
Both Buesler and Siegel emphasize that this should not be seen as a substitute for ending the use of fossil fuels. This is still important in terms of giving them a chance to beat climate change. But there is also a need to develop decarbonization strategies to reduce the greenhouse gas load in the air to avoid the worst effects of climate change.
“Even if we remove carbon from our economy, there will still be about 20 gigatonnes of carbon dioxide that must be removed from the atmosphere to keep us close to the goals of the Paris Agreement,” Siegel said.