Distributing iron particles produced by bacteria could "fertilize" microscopic ocean plants and ultimately lower atmospheric carbon levels, according to a new paper in Frontiers.

"It is important that we explore ideas for climate change mitigation that can supplement the effects of decreasing carbon emissions," said David Emerson, a senior research scientist at Bigelow Laboratory for Ocean Sciences and author of the paper. "The more ideas we test, the better decisions we can make for our planet's future."

Emerson's paper proposes a novel way to provide iron to large areas of the ocean, 30 percent of which is poor in the essential element. This method takes advantage of minerals synthesized by iron-oxidizing bacteria, which feed on the tiny spark of energy they generate by transferring electrons between iron and oxygen. This process produces rust minerals as byproducts, which are of the right chemical composition to be used by the tiny ocean plants called phytoplankton that help remove carbon dioxide from the atmosphere.

Iron-oxidizing bacteria live in environments as extreme as the deep ocean and as common as roadside ditches. Emerson believes that cultivating iron-oxidizing bacteria in shallow ponds could be a simple, inexpensive way to produce nanoparticles of iron that have specific properties needed to "fertilize" the ocean. Using iron fertilization as a climate change mitigation tool was first proposed in the 1990s, and Emerson believes implementing a controlled research program is the next step in exploring its efficacy.

"This research has tremendous potential to integrate disciplines from phytoplankton ecology, to atmospheric science, to engineering," Emerson said. "At minimum, we would gain a better sense of how the ocean works. At best, iron additions would act on a short time scale to help mitigate climate change."

Most iron enters the ocean as dust that blows seaward from the Sahara and other major deserts. Emerson believes that using aircraft to distribute a fine iron powder over deficient ocean regions would approximate natural iron inputs. Timing flights with seasonal phytoplankton "blooms" would stimulate growth and boost populations.

Phytoplankton live in the sunlit upper layer of the ocean, which is kept in chemical equilibrium with the atmosphere through constant exchanges between the air and sea. They grow using carbon dissolved in the upper ocean. When they die, some of the phytoplankton sink, sending that carbon to the deep ocean, where it remains for thousands of years.

As this cycle pumps carbon into the remote ocean depths, more atmospheric carbon diffuses into the upper ocean. Stimulating phytoplankton growth with iron fertilization could ramp up this process, ultimately shuttling more of the excess atmospheric carbon into the deep ocean.

"In addition to cutting carbon emissions, we need to remove more carbon from the atmosphere to limit global climate change," Emerson said. "These geoengineering approaches are not solutions to the whole problem, but they are potential ways we can mitigate the worst effects."

Evidence in the geologic record indicates that the amount of iron captured by the ocean may have helped moderate global climate in the past and played an important role in controlling earlier ice ages. When events like volcanic eruptions add large amounts of iron to the atmosphere, they may have the effect of fertilizing the ocean - increasing phytoplankton activity and ultimately carbon drawdown.

"It's important to start investing in thoughtful and extensive research programs now," Emerson said.

"The worst thing would be if, in several decades, people faced with horrible consequences of climate change started taking dramatic action without understanding the long-term effects. We need to explore and develop a continuum of solutions, from actions we can take as individuals to large-scale efforts."

Research paper

Related Links
Bigelow Laboratory for Ocean Sciences
Climate Science News - Modeling, Mitigation Adaptation

Tweet

Thanks for being here; We need your help. The Space Media Network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceMediaNetwork Contributor $5 Billed Once credit card or paypal		SpaceMediaNetwork Monthly Supporter $5 Billed Monthly paypal only

Eco-tax championed, contested and still marginal in EU
Paris (AFP) March 31, 2019
Taxes on products considered polluting are struggling to gain ground in the European Union despite backing from Brussels, in the face of strong opposition from movements like France's "Yellow Vests". In 2011 the European Commission envisaged that by "2020 a major shift from taxation of labour towards environmental taxation... will lead to a substantial increase in the share of environmental taxes in public revenues". So far this has not come to pass. Since then the share of environmental tax rev ... read more