How we beat the climate crisis by 2075

Five stylized pathways to a stable climate

Futuristic New Year’s Eve AI slop courtesy of ImageFX.

It is 1 January 2075.

The climate crisis is over.

After a frightening peak in the mid 2040s, mean global temperatures and atmospheric greenhouse gas concentrations both began falling over the next decade and are now on their way back to pre-industrial era levels, as is ocean pH. Arctic ice cover has stabilized. Sea levels have stopped rising.

The world still has plenty of problems, environmental and otherwise. But climate chaos has become something kids learn about in history class.

If we get there, how will we have done so?

I can think of five pathways.

Realistic pathways. Pathways that don’t imply crazy unworkable things like world government or overthrowing capitalism or abolishing industrial society. Pathways where ongoing decarbonization comes together with gigaton-scale carbon dioxide removal without having to posit wild discontinuities in our technology, our institutional plumbing or our inherent nature.

I assume we’ll continue to decarbonize the economy slowly, because that’s what history has shown is feasible. If that’s the case, stabilizing the climate will mean removing greenhouse gases from the atmosphere quickly, because there is no other way to make the math work.

Below, are five stylized narratives about what it would take to make this happen. Reality will surely be much messier, and will include some mix of these.

Still, for clarity, let’s pry the five pathways apart, starting with:

10x Cheaper Energy

There are any number of ways to capture carbon dioxide from the air or the sea. Most have the same problem: they’re too expensive, because they’re too energy-hungry. That means a fundamental breakthrough that makes energy much cheaper would solve the Carbon Dioxide Removal conundrum more or less overnight. Everything from Direct Air Capture to Ocean Alkalinity Enhancement and many others would be easy peasy if power was much cheaper.

In this future, we see a major energy breakthrough sometime in the 2030s that reduces everyone’s power bill by 90% or more within a decade.

That breakthrough could come from any of several lines of active research.

Solid state batteries of the kind several car companies are working on would do it, but so would advanced nuclear fission. It could take the form of a breakthrough in nuclear fusion, or in the still-speculative, potentially-transformative Solid State Fusion technology my organization, the Anthropocene Institute, supports. Alternatively, a fundamental advance in drilling technology would unleash order-of-magnitude cheaper geothermal that you could deploy anywhere.

Whichever breakthrough sets the world on this pathway, by 2050 it transforms the intractable carbon sequestration problems of the first half of the century into the straightforward engineering projects of the second half. Much cheaper energy would solve climate and many other problems besides, so it makes sense that so much effort is going into this.

This remains our brightest hope, but it’s by no means a done deal.

And if we don’t get much cheaper energy, we’re going to have to rely on marine photosynthesis, in one of four ways.

Sargasso Breakthrough

Nothing that lives captures carbon faster than Sargasso — the floating seaweed so productive that it gives its name to a whole sea. Hated by Caribbean beachgoers for its preternatural ability to gum-up holidays, Pelagic Sargassum has long been recognized for its unique ability to turn carbon dioxide into biomass fast, without even needing to be anchored to anything.

In this scenario, research into sargassum-derived biopolymers and fuels accelerates through the 2020s. By the mid-2030s, we get our first Sargassum billionaire, after her company corners the market in zero-carbon aviation fuels.

This sets off furious competition, with more and more producers figuring out new and better ways to grow sargassum at scale, delivering feedstocks to more and more biorefineries that turn sargassum into carbon-storing products in everything from textiles and packaging to the construction industry.

By 2045, the industry hits a milestone with sargassum-derived plastics becoming cheaper than petrochemical plastics for the first time, and from here growth just becomes explosive. Slowly at first, then more quickly from the mid-2040s, the petrochemical industry morphs into the sargassochemical industry. Farmed sargassum achieves gigaton-scale sequestration for the first time in 2050, and by the 2060s sargassum-derived biofuels and materials have replaced what remained of the old oil industry.

Virtually the entire South Atlantic has by now become an enormous Sargassum farm, and massive industrial biorefining facilities in Brazil, Argentina, Nigeria, Gabon, and South Africa sequestering sargassum at scale, as Sargassum’s prices are reported in the news the way oil prices used to be.

This, I’m aware, sounds fanciful. But some of the best minds in climate are certain this is the way forward. I would not bet against them.

WHOI to the rescue

Big seaweed like sargassum is interesting, but most researchers think the future is at the other end of the algal size scale. Phytoplankton—microscopic plant-like beings—are excellent carbon sinks, and fertilizing them is an idea that just won’t go away.

By far the best-resourced effort to make gigaton-scale phytoplankton CDR work is Exploring Ocean Iron Solutions, the big scientific push from the venerable Woods Hole Oceanographic Institution.

Woods Hole —WHOI, to friends— is the 800-pound gorilla in ocean iron fertilization: they have more scientists, more funding, more expertise, more equipment and more institutional backing than anyone else. If anyone is going to make this work, it should be WHOI.

Their plan is to run a large-scale trial in the Gulf of Alaska to nail down a specific methodology to first measure and then optimize carbon transport to depth via ocean iron fertilization. Their approach is very much that of a non-profit, so they plan to make all their findings public.

What happens if this goes well? A first series of tests in the late 2020s leads to a robust Monitoring, Reporting and Verification protocol that Woods Hole just straight up publishes on its website.

From there, we’re off to the races. By the mid-2030s, researchers worldwide are building on the WHOI protocol to launch ocean fertilization efforts, competing with one another to find new places where this can work. As they refine WHOI’s methods, competition kicks in and the cost-per-ton of carbon sequestration falls quickly. Hundred-year sequestration credits begin at around $60 a ton, but by the mid-2040s they’re half of that.

Initial concern melts away as the ecological benefits of the technique come into focus. Fisheries’ hauls keep rising and fish prices keep falling wherever WHOI’s methods are applied. As whale populations begin to grow, green skepticism to WHOI’s approach can’t find a foothold.

By 2050, what comes to be known as sons-of-WHOI (independent groups —some public, some private— working to improve WHOI’s protocol) are selling credits around the $10 per ton mark, leading to a flood of new investment as the sector grows quickly. Governments, realizing no cheaper CDR method is on offer, become big ticket buyers for these carbon credits.

The sector hits 10-gigaton per year scale by the mid 2050s, with sons-of-WHOI fertilizing oceans at scale, putting the world in a trajectory to make climate chaos history by 2075.

Gigablue makes gigabucks

Of course, WHOI’s not-for-profit approach isn’t the only game in town. There are also profit-motivated ways to make this whole field take off.

Take Gigablue. This scrappy startup has beaten everyone to the punch, landing a research permit from the government of New Zealand last year to begin trialing their innovative approach to ocean photosynthesis-based carbon removal. Gigablue has already started signing offtake agreements with aviation industry buyers. Those credits are expensive, sure, compared to where they might be. But then, they’re first in the market—they can command a premium.

Now imagine they make it. Big time. By 2028, Gigablue has signed a $1-billion deal to remove 10 million tons of carbon dioxide. They deliver, and by 2030, they’re signing $5-billion deals, for 50 million tons. A couple of years later, they’re at five times that size. Soon, the peeps who launched the company find themselves shopping for yachts and private jets. They’re making huge margins on a supremely scalable technology.

What happens then?

Inevitably, they’re going to attract copy-cats. By the mid-2030s, Gigablue won’t have the market to itself. Of course not! With margins like that, competitors are going to enter for sure. By the late 2030s, five companies with similar-but-different protocols are out there making aggressive bids for Gigablue’s market share. A price war ensues. Slowly but surely, the cost of carbon credits falls to match the cost of capturing the marginal ton of CO₂. Which, by then, will low: under $10 a ton.

Let that dynamic play out and you’ll end up at gigaton scale within two or three decades.

It’s unavoidable.

Fisheries first

But then, those last two scenarios imply carbon offset markets developing to the point where they can sustain gigaton-scale carbon removals. But that’s not a given. The “voluntary market” we have now is pretty anemic, and there’s a possibility it never develops beyond its current, embryonic stage.

Even without a working carbon credit market, though, phytoplankton could still do the heavy lifting of capturing tens of gigatons of carbon dioxide a year. Because, like sargassum farming, ocean iron fertilization could create its own revenue stream. Not via exotic biopolymers and fuels, but through something far simpler: fish.

This pathway starts in the late 2020s. As well as capturing carbon, fertilizing phytoplankton produces enormous amounts of fish food. Somebody somewhere is going to put it together that you can revitalize a struggling fishery by feeding the phytoplankton that feeds the fish.

When that happens, several things are likely to occur in quick succession.

First, fisheries officials in neighbouring countries are going to notice, and are going to want to get in on the action. Then they’re going to inquire how much an ocean fertilization program costs. Then they’re going to plug that number into their revenue model, and they’re going to realize they can make quite a significant amount of money by selling licences to fish in fertilized waters. And then they’re going to line up to ask the researchers to come do the same thing in their ocean patch.

They won’t be thinking about carbon. Not primarily; not at first. They’ll be sequestering carbon almost despite themselves, as a byproduct of an entirely different set of priorities. But by the 2040s, the amount of carbon they’re sequestering almost by accident is going to be so significant, it’ll be impossible to ignore.

Somewhere along the line, an enterprising young mind is going to figure out fishing fleets can supplement their income by issuing credits on the side to monetize the carbon that gets sequestered in the deep sea rather than ending up in the food chain. Carbon credits could become a nice little side-earner for them.

Most of the carbon this approach captures will end up parked in biomass, inside the bodies of the plankton and the krill and the fish that these interventions are aimed at feeding. The result would be a uniquely resilient carbon sequestration strategy, one that doesn’t sweat the ups and downs of donor interest in carbon removal because it doesn’t rely on donors for its survival, it depends on fisheries and, ultimately, fish consumers.

As it develops through the 2040s and 2050s, the market for fertilization will expand, eventually taking in entire ocean gyres and turning vast marine deserts into enormous carbon sinks. As fish production increases, prices will fall, and consumers will begin to substitute fish for meat in their diets, reducing emissions from land. Carbon credits may play a role in monetizing this approach — but not the predominant role.

So which of these five stories do I think is likely to be realized? All of the above. The untrammelled shangri-la of climate health by 2075 will most likely require a combination of these approaches, with perhaps some Marine Cloud Brightening, some Stratospheric Aerosols and some atmospheric methane removal on the side to take the edge off of the heat while CDR ramps up.

But if you absolutely force me to say which of these five pathways will predominate, I know which way I’d go.

I’d go with the approaches that don’t depend on carbon credits: the fisheries, especially, and the sargassum.

Because, deep down, I can’t bring myself to really believe that the voluntary carbon market is a real thing, or at least a thing that will really scale.

I could very well be wrong. Of course. But I’m betting on fish and seaweed.