Trees, seaweed, and cyanobacteria appear to be the solution to global warming.
I see a few reasons for hope on the global warming front. I see this hope because, well, I’m an optimist, to begin with. But I also see solutions to global warming that may not require very much technological advancement to achieve. And that means the solution to the problem of global warming may actually be much cheaper to produce and deploy than we had thought before.
I’ve noticed a stream of articles about a study that was done to show that if we grew enough trees, we could remove two-thirds of the CO2 from the atmosphere alone. The Guardian offers a great example of one such article. Here, they demonstrate that if we planted and grew one trillion trees, we could tackle the CO2 problem far easier and more cost effectively than any machine we could produce. For life has known how to metabolize CO2 for at least 2 billion years.
This idea isn’t even just one of the top ten ideas, it is the best idea for tackling global warming, and would require just 11% of the available land on earth. With a worldwide, WWII-like mobilization, we could resolve much of the CO2 problem, indefinitely, just by growing trees.
I would even add that we could also take our food processing waste and use it as fertilizer to help things along. Years ago, an experiment was conducted in Costa Rica where an orange juice maker was asked to deposit all of their waste made from manufacturing orange juice in one spot. 12,000 tons of orange peels were deposited there, restoring the forest there. They even left a sign there, a sort of marker to let the scientists know where to find it. 20 years later, the forest covered the sign to the point where it was hard to find. This is something we can do to help grow more trees, too.
Want some more hope? How about a 5,500-mile patch of seaweed that has spread across the Atlantic ocean, from the Gulf of Mexico to the west coast of Africa? Gizmodo says that this could be the new normal. Sure, life goes where the love is, and if there more CO2 in the air, there will be more plants to metabolize the CO2. Seaweed can be the new C02 sink.
Seaweed grows very quickly, much faster than land plants, and according to the article just published by Gizmodo, that giant seaweed patch grew to gigantic scale in just 7 years. Just imagine what that is going to look like in 10 or 20 years. Of course, they do mention that the size of the seaweed bloom corresponds well to the rise in agriculture in South America, for the water runoff into the ocean contained fertilizer. That was partly feeding the seaweed. Still, that seaweed is a giant CO2 sink.
So how effective is that seaweed at chewing through CO2? Well, according to The Conversation, in an article published in 2017:
The stupendous potential of seaweed farming as a tool to combat climate change was outlined in 2012 by the University of the South Pacific’s Dr Antoine De Ramon N’Yeurt and his team. Their analysis reveals that if 9% of the ocean were to be covered in seaweed farms, the farmed seaweed could produce 12 gigatonnes per year of biodigested methane which could be burned as a substitute for natural gas. The seaweed growth involved would capture 19 gigatonnes of CO₂. A further 34 gigatonnes per year of CO₂ could be taken from the atmosphere if the methane is burned to generate electricity and the CO₂ generated captured and stored.
So seaweed covering just 9% of the ocean could capture 19 gigatons of CO2 in a year. in 2015, human activity produced an estimated 40 gigatons of CO2. That’s a nice big chunk of CO2 remediation, by nature alone. Now some of you may be wondering about that methane…
Methane is 84 times more potent than CO2 as a greenhouse gas. But methane has a weakness that CO2 does not. Methane reacts with oxygen when combined while CO2 does not. In fact, there was a time in Earth’s history that due to a lack of methane, the temperatures on earth were estimated to fall well below freezing. At that time, 2.3 billion years ago, the earth was a snowball.
This article from CalTech, published in 2005, details a very promising theory as to how earth entered a snowball period and got out of out it. There is also a not so promising possibility that if we screw up badly — in the wrong direction, we could enter a snowball period again. So what happened?
The short story is that about 2.3 billion years ago, the evolution of life gave rise to cyanobacteria. Cyanobacteria are capable of splitting water and CO2 to produce oxygen gas. At that time, methane was abundant in the atmosphere and as the cyanobacteria grew in population, they added enormous amounts of oxygen to the atmosphere, and that oxygen reacted with the methane in the atmosphere.
Caltech scientists estimate that in as little as 100,000 years, enough oxygen was added to decimate the methane content of the atmosphere. The drop in methane in the atmosphere was so precipitous, that temps dropped to 50C below freezing. Scientists estimate that the equator was covered with a mile thick sheet of ice so long ago.
We still have cyanobacteria. We still have methane in the atmosphere. And it is well known that as the planet warms, frozen blankets of methane in the ocean and on the land will be released. Therefore, it is still possible for us to go into a runaway greenhouse effect. But given the capacity for life to respond to changes in the climate, it is also possible, as the CalTech scientists noted in their article, to go the other way.
I’m hoping that we can stay somewhere in the middle. Like right about where we are now.