Carbon Capture and Sequestration
The Too-Often Ignored (at Great Peril) Approach to Carbon Reduction
Reducing future carbon emissions is essential. However, the economic, political, and social challenges involved make it unlikely that this will be sufficient or in time to avoid catastrophe. We must also give equal attention to capturing the carbon already released and returning it safely to the ground.
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The growing awareness of the dangers of climate change has brought home the necessity of making major reductions in carbon emissions. The EU, for example, wants to set a target of halving carbon emissions by 2050 in order to keep the rise in global temperature below 2°C. If the temperature increases more than this, there is the very real danger of triggering runaway climate change.
If runaway climate change takes hold, temperatures could easily rise another six degrees, and we would have a planetary catastrophe on our hands. Under such conditions, the human species could well become extinct, along with countless others.
As significant and challenging as a fifty percent reduction in 50 years may be, even this may be insufficient to avoid catastrophe. Recent studies have shown the planet is warming faster than earlier anticipated and a growing number of climate scientists believe that we will need to make greater reductions, and much faster. George Monbiot, in his book Heat, argues that that if disaster is to be avoided, the nations of the world will need to reduce emissions by as much as 80% in the next 10 years.
Could we achieve this? From a technological perspective, yes. Alternative sources of energy are well-established. The problems lie in making the transition to large-scale implementation. For various reasons—lack of funding, political inertia, existing investment in fossil fuels—they are not yet making major contributions to global energy production. What holds us back is not the lack of technology, but the lack of will. China, which now emits more carbon dioxide than any other nation, wants more economic growth before it will sign up to any reductions, and is fueling this economic growth by building coal-fired power stations at the rate of two-a-week. The USA, which has the greatest carbon emissions per person (five times that of China), will not sign up to any treaty unless China does, and does not want to set a 2°C limit on global temperature increases because it would be too costly. Nor are we as individuals free from blame. When it comes to giving up air flights, or our cars, or foregoing some of the comforts to which we have become accustomed, we often continue much as before—a token here or there, but nothing like the changes that are needed.
Even if all concerned were fully committed to the task of reducing carbon emissions to the degree that now looks necessary, it would still be a most challenging task. However, when we include political inertia, the social challenges, and the reluctance of the principal contributors to even sign on to such a program, most of us, if we are honest with ourselves, will have to admit that there is very good chance that we will not be able to make the necessary reductions in carbon emissions in time.
There are some who believe that we may have no more time left. Even if we were to stop all carbon emissions today, the carbon dioxide (CO2) that we have already released will continue to warm the planet by 0.1°C per decade for much of the next century, and we could still find ourselves in a runaway climate change scenario. Worse still, there is some evidence that we may have already triggered this disastrous scenario. The arctic is warming three times faster than the rest of the planet; already the tundra is begining to thaw, releasing the much more potent greenhouse gas methane into the atmosphere.
The consequences of failure are so dire that it is easy to go into denial, hoping that it is not too late, that people will change, and that we will be able to make it. Many in the environmental movement respond by seeking to spell out even more clearly the consequences of failure, doing whatever they can to motivate people, corporations and governments to change as rapidly as possible.
However, there is another option. One that could still save the day.
The Under-rated Approach to Carbon Reduction
As critical as it is to reduce future carbon emissions, it is equally critical, perhaps even more critical, to get much of the CO2 that as already been released—and which is responsible for the current warming—out of the atmosphere and back into the ground where it belongs.
This approach, known as carbon capture and sequestration, has until now been largely ignored, and for several reasons. The atmosphere is so huge, it would seem to be an impossible task. There are possible technologies, but they are not nearly so well-developed as alternative energy sources. Many are still only ideas on paper. Where technologies of carbon capture have been developed they are mostly for capturing CO2 from smokestacks. Valuable as this may be, it is still dealing with the problem of future carbon emissions. What we need are technologies that will remove from the atmosphere the carbon that we already emitted, and then sequestrate it (put it away) in a stable form.
It is to this end that Sir Richard Branson announced his $25 million prize (Virgin Earth Challenge) for technologies that could capture a billion tons of carbon a year from the atmosphere (about one tenth of what we now release each year). Nor is it just Richard Branson who believes we must make this an equally important approach to the problem. His team includes Al Gore, James Lovelock, Sir Crispin Tickell (former UK ambassador to the UN), and James Hansen, the head climate scientist at NASA).
A few prototype carbon capture technologies are showing promise. Some of the most interesting involve biochar (from bio-charcoal). In essence, these processes take vegetation, which has already captured CO2, reduce it to charcoal through a process that captures the gases released (which include hydrogen and other non-carbon fuel gases), and then turn the carbon into a natural fertilizer which is plowed into the ground. The net result is the carbon captured by the plants is now returned to the soil in a stable form
There are several positive aspects to this approach. It is strongly carbon negative, relatively low-tech, imitates nature, is local in application, and if applied on global scale could capture a significant proportion of our carbon dioxide emissions we release each year. Moreover, it would provide large quantities of fuel. So it has multiple positive effects.
This is just one example. Other possible approaches involve capturing carbon in large kelp beds or land-based algae tanks, bio-engineering bacteria that would absorb large amounts of CO2, and even artificial trees.
Some of the more high-tech solutions are, quite rightly, regarded with skepticism by environmentalists. The technological fix mentality is part of what has got us into this mess. However, since is becoming increasingly doubtful that we will be able to reduce future carbon emissions to the extent needed to avoid runaway climate change, it is essential that we explore the pros and cons of every possibility.
Another objection put forward by some environmentalists is that if people believe it is possible to remove carbon from the atmosphere, then they will be less motivated to reduce their own carbon emissions. This is a bit like saying that we should not seek to develop HIV vaccines, since it will discourage people from practising safe-sex. If as now seems likely, reducing future carbon emissions is not going to happen fast enough to prevent the disaster scenario, then carbon sequestration may be our only hope. If a few people were less motivated to reduce their emmissions, that is a small price to pay.
Moreover, we cannot afford to leave it to the Richard Branson's of this world, and the small but enterprising groups of people working on the development of such technologies. We need a global research and development project to address this need—something akin to the Apollo Project which put a man on the moon, but involving many nations, many research institutions, and with the funding necessary, to tackle the most critical project, one on which our fate, and that of many other species, depends.
The good news is that once we put ourselves to the task, we are generally much better at solving scientific and technological problems than we are at solving political and social problems. And it is the latter that are severely hampering our ability to reduce future carbon emissions to the levels needed.
Moreover, if we can do this, if we can collectively summon the will and resources to clean up the planet's atmosphere, we will have set a most valuable global precedent that will pave the way for tackling the many other environmental challenges.
Date created: 04/25/07