Ralph J. Cicerone, one of the nation’s leading experts on climate change, is an atmospheric chemist who has made major contributions to understanding ozone depletion and the behavior of greenhouse gases. Now president of the National Academy of Sciences, Cicerone is planning a new yearlong study, requested last year by Congress, to advise the nation’s policy makers on climate change. The study will offer guidance on how to cut greenhouse-gas emissions, what climate changes are inevitable, and what future research is required to understand these changes more clearly. Cicerone recently spoke with Technology Review’s chief correspondent, David Talbot.

Technology Review: What research still needs to be done to understand climate change?

Ralph Cicerone: One of the things I would put money into is a climate observing system. Today, we have a patchwork of ways we are observing climate and climate change–a historical legacy of low-tech methods of measuring temperature and precipitation. We’ve never even strategized carefully about how to create a longer-term climate observing system to tell us what’s happening and give us the basis of prediction that we need–both for climate research and to help us know how to adapt to a different climate.

TR: In what areas, for example?

RC: If you think about one of the biggest unknowns in climate change–the rate of ice loss and sea-level rise–we have to know more about ocean-water temperatures, not just at the surface, but at greater depths. To my knowledge, no one is even taking the data at the right places. I don’t think it could be done with remote sensing. It could be done with buoy systems and larger oceanographic operations. And this could take a lot of money, but without these data, we’re going to have big holes in our ability.

TR: It’s clear enough that there’s a vast gulf between human-caused greenhouse-gas emissions and the ability of the planet to absorb them.

RC: The fossil-fuel input to the atmosphere, in terms of carbon, is eight billion tons a year, and the net uptake capacity of the whole earth is about three billion tons a year. And the terrestrial biosphere is losing carbon, to the tune of 1.5 billion or 2 billion tons per year, mostly from deforestation. So the annual imbalance is six or seven billion tons.

TR: Given the unique scale and intensity of coal emissions, isn’t it already clear that we need to stop burning coal unless we sequester the CO₂?

RC: That’s easy to say but a lot harder to do. There is a great deal that can be done with efficiency of coal plants too. Today, they are 35 to 40 percent efficient. Just going to cogeneration alone can capture 60 percent of total energy. The climate issue is the new force that has to be taken into account in these decisions, and it has never been taken into account before.

TR: But what if you did take climate into account with regard to coal?

RC: What we know says that we’ve got to cut back on emissions from coal–severely. I’m not willing to say we have to stop all coal plants because I don’t know how it can be done, because our dependence is so great. But I am willing to say that from everything we know now, those emissions are going to have to be cut back severely.

TR: Is large-scale carbon sequestration feasible?

RC: I don’t think it’s been shown to be feasible yet. There are some major research questions, some of them geological, some of them chemical. On the chemical side, the question is whether CO₂ has to be captured as a gas or can be processed on-site into a solid. There are some interesting new ideas on how to grab the CO₂ using mineral chemical processes to make a solid, rather than just capturing the gas, and there could be a mixture of approaches. And on the geological side, the safety of long-term storage and the efficacy of it has yet to be demonstrated on the colossal amounts we are looking at.

TR: What’s the best strategy for transforming the energy infrastructure away from fossil fuels?

RC: Energy efficiency is the low-hanging fruit now, but it won’t get us as far as we need to get. The next big strategic view would try at least to change our transportation away from liquid-hydrocarbon-based internal combustion engines to electric-drive vehicles. If you can do that, you open up the possibility of using renewable and nuclear to make electricity. But as it is now, we cannot trade oil for electricity, because even if we had abundant wind and solar and nuclear electricity, we can’t use them in our transportation fleet. The research agenda would be on the effective widespread production of renewable and nuclear electricity, with storage of the electricity–which is the problem for wind and solar, of course–and distribution. This is where the electric power grid comes in, to move electricity longer distances without significant losses, extending it in terms of quantitative capacity and geographic spread, to reach the strategic goal of using electricity for transportation, as well as more renewable electricity to replace coal electricity.

TR: And longer term?

RC: Completely replacing fossil fuels, if that is the long-term goal–there you have to bring in more far-out technologies, like completely new materials for photovoltaics that take you three and ten times better than we have now. The electrolytic splitting of water to make hydrogen, for example–the demonstrations by Daniel Nocera at MIT and his Caltech colleagues of at least some laboratory-scale feasibility–could open up a pathway which otherwise might not be the one you go for: hydrogen fuel.

TR: Could new kinds of nuclear power be a big part of the answer beyond a couple of decades?

RC: Yes, as well as the kind of renewable energy for electrolysis of water, which most people wouldn’t have thought was the way we wanted to go. But if it turns out to work, then the question is, can we make hydrogen into a storage medium of choice?

TR: But isn’t federal nuclear R & D, if not dead, at least on life support?

RC: That’s right.

TR: That needs to change?

RC: I think so. We haven’t done a lot of what I would call university-scale research on nuclear. The U.S. has invested in large programs in fission and fusion. If you want to be involved in that work, you have to be a member of one of those huge teams which are now essentially international. There are people out there with ideas for alternative processes making electricity out of nuclear processes–different fusion targets, different mixtures of deuterium and helium and lithium and boron–and a lot of ideas haven’t been pushed very far.

TR: Do we need a federal research effort on planet-wide geo-engineering to limit warming by, for example, blocking some sunlight?

RC: I think we need the research. I try to separate research–essentially on paper–from tinkering with the system in the real world. Actual intervention to try a large-scale fix or solution–I think we should put some fences around that. There are a lot of necessary conditions that we haven’t started to seriously think about yet. But research, on the other hand, is not being encouraged, and I think it has to be.

TR: Why?

RC: Well, we’re going to learn about the system. For example, the iron fertilization of the ocean idea [to absorb carbon dioxide] that came out in 1990-91. It led to some really good science being done. I think the current reading is that iron fertilization is unlikely to be of much help. But what we’ve learned about the oceans has been extremely valuable. And I think a lot of geo-engineering research will probably lead us to say, “You know, this isn’t going to work, but we’ve learned a lot in the meantime.”

TR: So it’s not worth pursuing for its own sake, but for the ancillary benefits?

RC: Well, it’s too soon to say. I’ll be very surprised if geo-engineering research leads to a solution–very, very surprised.