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Geoengineering and the Fight Against Climate Change: An Interview with David W. Keith

02/16/2015 09:35 am ET | Updated Apr 18, 2015

On Tuesday, the National Academy of Sciences released a new report on geoengineering, the deliberate modification of the earth's atmosphere to mitigate the effects of global warming. Proposals for solar geoengineering include the use of aircraft to deploy sulfates at high altitudes, which would increase the earth's reflectivity. This, in turn, could lower the amount of solar radiation that reaches the earth, thus slowing the rate of global warming.

Unsurprisingly, there are a number of uncertainties and undesirable side-effects with this plan and some oppose even studying geoengineering. To date, there has been no major publicly funded research program in geoengineering. However, while the NAS report concluded that deploying geoengineering now would be "irrational and irresponsible", it was broadly supportive of public research to improve "understanding of the physical potential and technical feasibility of geoengineering approaches".

At the forefront of this research is David W. Keith, Gordon McKay Professor of Applied Physics and Professor of Public Policy at Harvard University and president of Carbon Engineering, a Calgary-based technology company developing methods to capture and sequester carbon dioxide. I spoke with him in advance of his February 17th talk at The Long Now Foundation in San Francisco.

"Geoengineering" has come to be applied to two groups of technologies, solar geoengineering and carbon dioxide removal. How should we distinguish between the two?
Solar geoengineering is cheaper and quicker than carbon dioxide removal and proposes to lessen some of the damage caused by CO2. When emissions get to zero, carbon removal allows us to back up in a way that is very important. But it's not relevant in the next few decades.

When did field of geoengineering really begin?
The modern history really begins at around the same time people appreciate the CO2 climate problem. The single most important document is a report given to President Johnson in 1965. It is pretty much the first report to a president that has a modern statement of the climate change risk, and it discusses what we would now call geoengineering as a potential response.

When did you get interested in geoengineering and, more importantly, what got you interested in the field?
I got interested in it at the same time I got interested in climate change policy, in about 1988-89. I think I was partly drawn to it because of the strong opinions and emotions it brings up.

That's one of the things about geoengineering that is so striking: people aren't just against geoengineering practice, they're also against geoengineering research. I cannot really think of another scientific field where this is the case. Do you have a sense of why this is?
Trying to do this kind of deliberate intervention is a step that is different from what humanity has done before. Of course you can argue that we have transformed the environment in all sorts of ways for agriculture, etc. But this is the first thing that is really planetary scale with a deliberate effect.

Another part has to do with the very strong, politically motivated commitment by some people in the climate activist world to only talk about emissions mitigation. They want to talk about renewable energy and nothing else. And while I think that large scale use of renewables is a very sensible thing to do, I think that this attitude is a kind of dangerous monomania. Steve Rayner has said it is like the Southern Baptist attitude towards sexual education--if you don't talk about it people won't do it.

You yourself have spoken about the so-called "moral hazard" with geoengineering research, the risk that once geoengineering is on the table there won't be an impetus to cut emissions. How do you rank it as a risk?
If you are deciding policy based on balancing the cost of emission cuts against climate change risk, and you lower the climate change risks a little bit with geoengineering, you should of course lower the amount of emissions reductions a bit. That makes people profoundly uncomfortable, but I think they are not being honest about the public policy trade-offs involved.

The separate concern, that geoengineering as a response to climate change reduces willingness to cut emissions, is more understandable. But if you look at actual polling you see just the opposite effect. The fact that geoengineering is on the table makes climate change more frightening and so makes people more wiling to act.

There is still another framing. The way the environmental community currently talks about climate change, at best we can have a little bit less of a disaster if we pay a whole lot of money. My most optimistic view is that having solar geoengineering on the table, in combination with reduced emissions and eventually carbon removal, limits both near and long term risks from climate change. That could give people a sense that there is a potential win here, and get more political will to spend money on emission cuts now.

Despite the title of your book [The Case for Climate Engineering], you've repeatedly said you are not in favor of any immediate deployment because "the early science might be wrong". So are you making a case for climate engineering, or a case for researching climate engineering?
I don't advocate doing it now, but more than most of my colleagues I do advocate for it in the near term. If we do serious research, if that research is international, if it does not turn up any wild surprises and confirms the data we have now --and that's a real if, it might not--I think the balance of evidence suggests we should start a moderate program of solar geoengineering sooner than later, in 2020, so that we can learn as we go and actually get some benefit for people in the most vulnerable ecosystems now.

Geoengineering is relatively cheap--you've said a program costing $1 billion a year could have substantial effects. So in theory a single country--or wealthy person for that matter--could decide to start deploying this tomorrow. Should geoengineering only proceed with a formal treaty and the blessing of the UN?
We need international dialogue and collaboration but I'm not sure we need a formal treaty. And if geoengeering does happen I think the dynamic will be very simple. Some countries will do it--likely not the US--other countries will publicly say "we decry these actions without a UN treaty" but privately be happy because someone else is taking the heat and they get the benefit.

Do you see parallels between geoengineering and other controversial research areas such as genetic modification?
There are some similarities but also big differences. There are very legitimate reasons to say we should never geoengineer, but there is no legitimate view that early experiments are physically dangerous. However it is conceivable that if you do a lab experiment on a virus with some new genetic technology, there is at least some risk, perhaps infinitely tiny, that something could go awry and wipe out the entire human population. There is some experimental risk with genetic engineering in a way there isn't with geoengineering.

So then what's holding you back on conducting your proposed research?
The government wont fund it. And I think it's important in a democracy that these experiments go through a proper external risk assessment with substantial public funding.

Do you see any big changes in the debate on the horizon that could open up more support?
The National Resource Defense Council (NRDC) and other environmental groups have traditionally said geoengineering research is unenvironmental--which is unfair since many of us including myself have had a long history in environmental advocacy. But on Tuesday NRDC released a statement basically saying that while they prefer emission cuts and don't like the idea of geoengineering, they agree it should be studied. And that was a big deal for them to say that.