First Annual Ranking of Top 3 Carbon Sequestration Technologies
First Choice: Iron Fertilization
Risk: Low (see explanation below)
Iron fertilization is an interesting story. It has the best potential feasibility, low cost, and “scalability” -- in theory it could be scaled up to very large amounts. Actually it would be better if considered on a smaller scale…more about that below.
Yet as we’ve discussed in earlier posts ( link1, link2, link3), it has attracted major resistance and triggered hysterical prognostications of doom and environmental devastation by certain critics. Investigation of the science has been painfully slow, even stalled. The situation is so sad that we’ve published an Open Letter to the Marine Science Community .
Risks have probably been overblown or misinterpreted. Although there is a chance that the technique won’t work or will cause damage, it’s more likely that it can be tuned to be safe, controllable, and positive for the ocean ecosystem.
How to resolve the impasse between critics and proponents? Why do we think this process deserves a “low” risk rating? Here’s a proposal:
The sticking point has always been size. Scientists debating the process have assumed, as a starting point for discussion, that iron fertilization must be done on a massive scale to soak up all of mankind’s excess carbon (so-called “geo-engineering”). But this is a logical fallacy – it is not necessary to evaluate the process only on a gigantic scale. And in any case, the consensus of the world climate change community is that no single technology is expected, or even desired, to do the entire job single-handedly.
So what if we focus on small and medium-scale applications? Even staunch critic Sallie Chisholm stated that iron fertilization if done in local patches would be likely safe, could be monitored, and would not affect the ecosystem permanently.
Is this a workable strategy? Absolutely. Consider that any commercial or government agencies starting these projects, at least in the first few decades, could only do projects which by definition qualify as “small” on an oceanic scale, even if they sequester a comparatively large amount of carbon. Projects would naturally start small, grow slowly. Even if faster growth was possible, the available investment money wouldn’t support it. All activity, in order to qualify for carbon credits, would have to be completely transparent for oversight by concerned parties.
The key step, as anyone experienced with environmental restoration, is to get out in the field and give it a try. A reasonable approach would be a partnership between commercial ventures, willing to risk seed capital, along with major ocean science labs, willing to study feasibility and underlying processes, both working under the aegis of the Kyoto development mechanisms, and closely monitored by science and environmental groups.
As these first projects begin, this will funnel significant new funding into the monitoring and testing of deep ocean conditions by growing ranks of marine scientists. This growth in funding and public attention would itself provide additional data on long-term effects.
Above all, the Marine Science field needs significant funding increases to accelerate their understanding and resolve further questions. Given the enormous sums being poured into much less likely and more risky technologies, this one is getting shortchanged
For all these reasons, we believe that Ocean Iron Fertilization is still the best opportunity in sight, if it is approached less emotionally, and more practically.
Second Choice: Reforestation and Agricultural Sequestration
Who doesn’t like growing more trees? If we can grow more trees intelligently, we can restore forestlands, improve quality of life, and create a short-term fix to remove a bit of carbon dioxide from the air at the same time.
Reforestation projects are underway in a hundred different locations in the developed and developing world. There are still obstacles, but the risk is non-existent and the science well understood.
Note that reforestation and improved agricultural practices fit the long-term trends of the world. As people move to less agrarian lives, they are removing the burden of over-cutting that has reduced forests, and appreciating the pleasures of restored forestlands. Reforestation therefore has social and national benefits, in addition to its environmental benefits.
In the tropics, this process has yet to take hold. Deforestation, slash-and-burn framing, is still an enormous problem. Reforestation for carbon credits could be one more tool to prevent this.
It’s good for the land, good for the animal species, good for the ecosystem, and good for the human soul. It’s a win-win.
Unfortunately, Reforestation is a slow-growth business that has some significant limits on size and scale. Planting trees is slow, and growing trees is slow. It’s expensive to do. Therefore it drops to second place in our ranking.
Third Choice: Geologic Sequestration
Finally, there is geological sequestration. Despite great unknowns, this is the biggest “technologically driven” method of sequestering fossil fuel emissions, most significantly from coal burning power plants.
Coal is the economic driving force for many nations, including the US and China. While it’s nice to dream that we could shut them down, the fact is, global warming or not, we’re not going to. That kind of political will doesn’t exist and it never will exist, despite the hopes of the Green community. The best option we have, which almost all politicians acknowledge, is to try to store away the carbon while we continue converting energy infrastructure to non-carbon emitting.
The key to geologic sequestration is that it can be done with exhaust gases straight from the emitter. For this reason it has a certain attraction.
The strategies studied include:
1. Coal seam injection – CO2 is pumped deep into un-reachable coal deposits, where is soaks into the coal.
2. Oil well injection – CO2 is pumped into oil fields, where it helps push the oil up and out. Eventually, after the oil is gone, the wells are capped and the CO2 is kept inside.
3. Underground brine or rock formations -- CO2 is pumped deep into underground brine salt or rock formations which seem capable of containing the gas permanently.
In theory these methods could store monumental amounts of gas. There is a lot of territory underground. Coal seam and oil well are especially attractive for simple reason that they seem to put “back” the carbon where it was taken “out”. Of course this isn’t exactly correct, and any engineer would shake his or her head. Oil well injection has an even better story: it helps pump out more oil. This may mediate the cost somewhat.
Unfortunately, geological sequestration has significant risks and uncertainty as well.
- It’s very cost intensive. The cost of separating and compressing the gas, then pumping it underground, is significant. Best estimates show that geological sequestration would increase the cost of coal generated power, for example, by 25 to 50%
- Nobody is sure it will work. This is a very big engineering challenge. Power plants emit huge clouds of gas every day. If pumped underground it could easily leak from many cracks and fissures.
- It could be risky. If a “cap” were to pop and a huge body of gas rushed out, it could smother humans and animals near the ground.
- Easy (and a lot of incentive) to cheat. Here’s the problem that few people mention. Unlike other types of sequestration, this one is a direct daily expense for a coal plant. Every hour they run the compressors to pump the gas underground, they are losing thousands or perhaps millions of dollars. If they could just turn those pumps off, suddenly they would be making a LOT more money. For a typical power plant manager, who is probably paid his annual bonus based on how efficiently he runs his plant, the temptation to cheat, to “let the compressor break”, to “accidentally turn it off” would be unbearable. It’s an invitation to cheat the system.
Geological sequestration is therefore our 3rd choice for carbon sequestration. It has a long way to go to prove it can work, but the potential it huge.