written 25 June 2023
published 2 July 2023
It's hot! Much of Texas was over 110°F, with Corpus Christi enduring 125°F heat index after nine consecutive day of heat index above 115°F. Oklahoma experienced 3" hail, and an EF-3, 150mph, tornado hit Mississippi. NOAA declared a Category 5 marine heatwave, with sea temperatures as high as 9°F above normal, affecting 40 percent of the ocean, threatening to disrupt not only all sea life, but global wind and sea currents as well.
In the last 50 years humans have added as much atmospheric CO2 as the change from the last ice age to the current period when civilization thrived. A habitable climate for our children requires we decarbonize the economy and sequester 1,000 billion tons of CO2, as soon as possible. This is the thesis of the book "Climate Restoration", by Fiekowsky and Douglis, which suggests 4 paths to achieve this sequestration goal.
The third plausible method of returning to 300ppm by 2050 is Ocean Iron Fertilization (OIF): cultivating ocean phytoplankton with iron fertilization. Phytoplankton, which can photosynthesize carbon 40 times faster than trees, are the foundation of the entire ocean food chain. In the open ocean, growth can be limited by lack of critical nutrients, specifically iron. But when iron is added naturally, from volcanos or wind-blown terrestrial dust, these "desolate zones" bloom. What is not eaten falls to the sea floor, sequestering the carbon for centuries.
Dr. John Martin, former director of the Moss Landing Marine Laboratories, first seriously promoted intentional OIF decades ago, and small-scale testing demonstrated the process works, showing best results in natural ocean eddies, which kept the iron from rapidly dispersing, and areas where iron was the only limiting nutrient.
In 2012, Russ George, working with the Haida First Nation in British Columbia, completed a larger OIF experiment 200 miles off shore, with the goal of helping restore the native salmon run. They spread 110 tons of iron over 10,000 square kilometers. Within hours the ocean turned green, and within days, thousands of seabirds were diving, whales beyond count arrived, and massive schools of albacore tuna showed up, fattening from emaciated to sashimi grade within two weeks. The bloom lasted for months, eventually expanding to 35,000 square kilometers. The following year, the returning salmon run was the largest on record, and the next year the local orca population enjoyed a "baby boom".
Ocean life had flourished and megatons of carbon had been removed from the atmosphere. Applying OIF to just one percent of the ocean, funded by licensing the fishing industry, could enhance ocean life and sequester 50 billion tons of carbon each year.
However, the 2012 experiment stirred great controversy, with concerns of unintended consequences. Some feared the success of OIF would give the fossil fuel industry no reason to curtail their toxic industry. However, rapidly depleting fossil reserves, economic advantages of EV transportation, reduction of air pollution health issues, and reduction of geopolitical stress, will support sustained public pressure for decarbonization.
Some fear OIF would "turn the ocean into a pea soup with toxic algae blooms". Yet toxic algae blooms are a product of near shore human nutrient runoff, and deep ocean blooms are already a natural occurrence. Further, the OIF blooms would dissipate in a few months, as the eddies dissolves.
There is concern that "dumping vast amounts of iron into the ocean is reckless". But the amount of iron needed, 10 pounds per square mile, is 1/10,000 the amount in coastal waters. Commercial farming adds 90,000 times as much on corn crops. To sequester enough carbon to get to 300ppm by 2050 would affect about one percent of the ocean, while agriculture uses 37 percent of the land.
Important issues are still unclear. Much of the phytoplankton is eaten, so how much carbon is actually sequestered, and for how long? Will large blooms critically deplete other essential nutrients, creating "dead zones"? Will this change distribution of fish and whale populations? How will results be verified?
However, the climate crisis, a consequence of a perspective that assumes only humans are important and money is all that "counts", is already adversely impacting the planet, threatening all life. A habitable future is worth taking a risk. This process nourishes life, with a goal of returning to a condition we know has supported humans: atmospheric CO2 at 300ppm. We have to make a start, understanding we must carefully monitor the process, and adjust over time.
