Exchange of Fire: Should CO2 go underground?
Emitted to the atmosphere, carbon dioxide is wreaking havoc with our climate. And there’s a lot more in the pipeline, until the world can be weaned off fossil fuels. So what about capturing and storing the CO2 – sequestering the carbon – in the meanwhile? Trees do that, naturally, but is there a better future in locking it underground – and aren’t those vast saline aquifers the ideal place? Roger East chairs the debate. | YES | | NO |
| Andrew Chadwick, principal geophysicist at the British Geological Survey, and one of the Sleipner sequestration experiment monitoring team | | Paul Johnston, principal scientist at the Greenpeace Research Laboratories |
Andrew Chadwick: We need to cut CO2 emissions quite drastically in the next few decades. Just to stabilise atmospheric levels (at say 450-550 parts per million) requires a reduction of 25% in the next 20-30 years, and deeper cuts of the order of 60% are necessary in the longer term. The question is, how do we achieve this? The cheapest CO2 savings come from updating old power stations, but this won’t take us far enough. Investment in renewable energy, by contrast, has high potential (offering near-zero emissions) but much higher costs. For somewhere like the UK, too, reliance on renewables raises real issues of space. How much room do we have for wind farms, and can we realistically cover the countryside with crops for biomass? Carbon sequestration is a ‘middle way’, a moderate cost response with high potential for keeping CO2 out of the atmosphere. But sequestration does not necessarily mean forestry, which isn’t a particularly secure way of storing carbon; just look at the scale of destruction of European forests in recent storms and the increasing incidence of fires. The technology I’m proposing involves collecting CO2 from our major industrial emitters and storing it in underground formations. Disused oil and gas fields are one possibility. The best option, however, is secure long-term storage in saline aquifers – vast underground rock formations, at a depth of 1-2 km beneath the earth’s surface, whose pore spaces are filled with salt water – into which we can pump CO2 instead.
Paul Johnston: Certainly we need to take action on CO2 emissions. Climate change is, unarguably, one of the major threats facing mankind and the global environment, and we should look carefully at any potential contribution to mitigation. That includes carbon storage options – some more promising than others. It’s important to distinguish between them, and I acknowledge that there seems to be real potential in saline aquifers. But we need to understand the full scope of these approaches. How can you be 100% certain that you’d be locking the gas up long term? Even very low leakage rates would negate any possible benefits. And even if it were possible to meet all the concerns about leakage, the integrity of geological formations, the impact on ecological systems within the aquifers, there’s a wider issue. These storage proposals mark a crossroads in our strategic approach. We get all concerned about cutting emissions, and then along comes a macro-engineering solution. Suddenly it’s the flavour of the month. The coal industry’s behind it, the oil industry’s behind it, geologists are behind it. Within a politician’s five-year timescale, what will people say? “CO2? We’re going to put it all down holes in the ground, we don’t need to bother with renewables any more.” But trapping, purifying and storing CO2 are all very cost-intensive. Committing to this route could mean we are precluded, financially and economically, from more sustainable solutions.
Roger East: Two big questions for you there, Andrew: will it work, and – if it does – is it still a red herring in the big picture?
AC: Will it work? Yes. We can say with a high degree of certainty that CO2, liquefied and stored in a saline aquifer with an effective seal, will remain there for geological timescales – hundreds of thousands of years, perhaps even millions. The science of how buoyant liquids behave is well understood. What’s more, where the boundary layer of CO2 comes into contact with the surrounding aquifer geology and the sealing cap rock, the ensuing chemical reactions may well be helpful, reducing permeability. Admittedly it is much more difficult to predict leakage from oilfields, where liquid CO2 may be pumped in for enhanced oil recovery (or potentially just for sequestration), because they tend to be peppered with wells. But a lot of enhanced oil recovery has been carried out, so far, with no catastrophic leakages. At Florina in Greece, a well started to leak CO2 – then, after 10 years, it self-sealed, apparently as a result of a build-up of carbonate. Remember, too, that large natural accumulations of CO2 underground have remained stable over millions of years. And, where it does leak to the earth’s surface, it’s not toxic, flammable or explosive. Locally, natural CO2 leaks have become tourist attractions, or carbonated mineral water.
PJ: Contrast that with Mammoth Mountain in California, where seepage up through the soil was found to have suffocated tree roots and produced lethal concentrations of CO2 in poorly ventilated buildings.
AC: But volcanic areas like Mammoth are precisely the kind of places you would not choose for CO2 storage.
PJ: In any case, the main issue here is not catastrophic releases from storage sites – that’s more likely when the CO2 is being transported, or in the pre-injection stages. But you might as well not bother sticking it down a hole in the ground in the first place with leakage of even fractions of 1%. Because this would mean that ultimately, it’s all going to come back out.
AC: That’s simply untrue. But just suppose we could only ensure secure storage for 500 years. Even this would get us past the point where CO2 concentrations in the atmosphere would otherwise peak – at say 900 parts per million – as a result of our fossil fuel use. Peak-shaving like that has got to be a good thing.
PJ: Ah, peak-shaving. The same argument as is being promoted for approaches such as injecting CO2 into the deep ocean. But we’d end up with a higher equilibrium situation than if we did nothing at all, simply because of the energy penalties involved in liquefying the CO2. And it violates an important precept of sustainability, that we should not be imposing constraints on future generations.
AC: The fact is that the vast majority of our energy at present comes from fossil fuels...
PJ: For which this is widely seen as a get-out-of-jail-free card...
AC: ...And the transition from fossil fuels, whether it takes 30 or 80 years, is not going to happen overnight. We have no alternative but to use fossil fuels for several more decades. CO2 sequestration enables us to dispose of a significant proportion of the consequent emissions, while we build up the huge infrastructure needed to get our energy from renewables. In my view there is no other way of doing it.
PJ: You are quite right that it is unrealistic to expect us to move to 100% renewables tomorrow. But you need to demonstrate a robust analysis of how the two strategies are going to evolve together. Make sure the one is not developed at the expense of the other. How much infrastructure would have to be built for sequestration – and how much investment would this deflect from renewables? There are other options – even the ‘do nothing’ option. And, unless you can guarantee that you are going to get the ‘peak-shaving’, you are holding out a potential false promise to people.
AC: We can, within reasonable bounds of certainty, guarantee that. Underground sequestration, we know, is technically practical. There is some minor disquiet about safety, but in my view the issues are tractable, and these techniques will keep CO2 out of the atmosphere for much longer than the 500 years required for peak-shaving.
Emitted to the atmosphere, carbon dioxide is wreaking havoc with our climate. And there’s a lot more in the pipeline, until the world can be weaned off fossil fuels. So what about capturing and storing the CO2 – sequestering the carbon – in the meanwhile? Trees do that, naturally, but is there a better future in locking it underground – and aren’t those vast saline aquifers the ideal place? Roger East chairs the debate.
| YES | | NO |
| Andrew Chadwick, principal geophysicist at the British Geological Survey, and one of the Sleipner sequestration experiment monitoring team | | Paul Johnston, principal scientist at the Greenpeace Research Laboratories |
Andrew Chadwick: We need to cut CO2 emissions quite drastically in the next few decades. Just to stabilise atmospheric levels (at say 450-550 parts per million) requires a reduction of 25% in the next 20-30 years, and deeper cuts of the order of 60% are necessary in the longer term. The question is, how do we achieve this? The cheapest CO2 savings come from updating old power stations, but this won’t take us far enough. Investment in renewable energy, by contrast, has high potential (offering near-zero emissions) but much higher costs. For somewhere like the UK, too, reliance on renewables raises real issues of space. How much room do we have for wind farms, and can we realistically cover the countryside with crops for biomass? Carbon sequestration is a ‘middle way’, a moderate cost response with high potential for keeping CO2 out of the atmosphere. But sequestration does not necessarily mean forestry, which isn’t a particularly secure way of storing carbon; just look at the scale of destruction of European forests in recent storms and the increasing incidence of fires. The technology I’m proposing involves collecting CO2 from our major industrial emitters and storing it in underground formations. Disused oil and gas fields are one possibility. The best option, however, is secure long-term storage in saline aquifers – vast underground rock formations, at a depth of 1-2 km beneath the earth’s surface, whose pore spaces are filled with salt water – into which we can pump CO2 instead.
Paul Johnston: Certainly we need to take action on CO2 emissions. Climate change is, unarguably, one of the major threats facing mankind and the global environment, and we should look carefully at any potential contribution to mitigation. That includes carbon storage options – some more promising than others. It’s important to distinguish between them, and I acknowledge that there seems to be real potential in saline aquifers. But we need to understand the full scope of these approaches. How can you be 100% certain that you’d be locking the gas up long term? Even very low leakage rates would negate any possible benefits. And even if it were possible to meet all the concerns about leakage, the integrity of geological formations, the impact on ecological systems within the aquifers, there’s a wider issue. These storage proposals mark a crossroads in our strategic approach. We get all concerned about cutting emissions, and then along comes a macro-engineering solution. Suddenly it’s the flavour of the month. The coal industry’s behind it, the oil industry’s behind it, geologists are behind it. Within a politician’s five-year timescale, what will people say? “CO2? We’re going to put it all down holes in the ground, we don’t need to bother with renewables any more.” But trapping, purifying and storing CO2 are all very cost-intensive. Committing to this route could mean we are precluded, financially and economically, from more sustainable solutions.
Roger East: Two big questions for you there, Andrew: will it work, and – if it does – is it still a red herring in the big picture?
AC: Will it work? Yes. We can say with a high degree of certainty that CO2, liquefied and stored in a saline aquifer with an effective seal, will remain there for geological timescales – hundreds of thousands of years, perhaps even millions. The science of how buoyant liquids behave is well understood. What’s more, where the boundary layer of CO2 comes into contact with the surrounding aquifer geology and the sealing cap rock, the ensuing chemical reactions may well be helpful, reducing permeability. Admittedly it is much more difficult to predict leakage from oilfields, where liquid CO2 may be pumped in for enhanced oil recovery (or potentially just for sequestration), because they tend to be peppered with wells. But a lot of enhanced oil recovery has been carried out, so far, with no catastrophic leakages. At Florina in Greece, a well started to leak CO2 – then, after 10 years, it self-sealed, apparently as a result of a build-up of carbonate. Remember, too, that large natural accumulations of CO2 underground have remained stable over millions of years. And, where it does leak to the earth’s surface, it’s not toxic, flammable or explosive. Locally, natural CO2 leaks have become tourist attractions, or carbonated mineral water.
PJ: Contrast that with Mammoth Mountain in California, where seepage up through the soil was found to have suffocated tree roots and produced lethal concentrations of CO2 in poorly ventilated buildings.
AC: But volcanic areas like Mammoth are precisely the kind of places you would not choose for CO2 storage.
PJ: In any case, the main issue here is not catastrophic releases from storage sites – that’s more likely when the CO2 is being transported, or in the pre-injection stages. But you might as well not bother sticking it down a hole in the ground in the first place with leakage of even fractions of 1%. Because this would mean that ultimately, it’s all going to come back out.
AC: That’s simply untrue. But just suppose we could only ensure secure storage for 500 years. Even this would get us past the point where CO2 concentrations in the atmosphere would otherwise peak – at say 900 parts per million – as a result of our fossil fuel use. Peak-shaving like that has got to be a good thing.
PJ: Ah, peak-shaving. The same argument as is being promoted for approaches such as injecting CO2 into the deep ocean. But we’d end up with a higher equilibrium situation than if we did nothing at all, simply because of the energy penalties involved in liquefying the CO2. And it violates an important precept of sustainability, that we should not be imposing constraints on future generations.
AC: The fact is that the vast majority of our energy at present comes from fossil fuels...
PJ: For which this is widely seen as a get-out-of-jail-free card...
AC: ...And the transition from fossil fuels, whether it takes 30 or 80 years, is not going to happen overnight. We have no alternative but to use fossil fuels for several more decades. CO2 sequestration enables us to dispose of a significant proportion of the consequent emissions, while we build up the huge infrastructure needed to get our energy from renewables. In my view there is no other way of doing it.
PJ: You are quite right that it is unrealistic to expect us to move to 100% renewables tomorrow. But you need to demonstrate a robust analysis of how the two strategies are going to evolve together. Make sure the one is not developed at the expense of the other. How much infrastructure would have to be built for sequestration – and how much investment would this deflect from renewables? There are other options – even the ‘do nothing’ option. And, unless you can guarantee that you are going to get the ‘peak-shaving’, you are holding out a potential false promise to people.
AC: We can, within reasonable bounds of certainty, guarantee that. Underground sequestration, we know, is technically practical. There is some minor disquiet about safety, but in my view the issues are tractable, and these techniques will keep CO2 out of the atmosphere for much longer than the 500 years required for peak-shaving.
RE: And you aren’t concerned that this could take the heat off, reduce the urgency of efforts to switch from fossil fuels to renewables, just when we need to keep the heat on?
AC: It would be a triumph if we could sequester enough CO2 to take the heat off!
Emitted to the atmosphere, carbon dioxide is wreaking havoc with our climate. And there’s a lot more in the pipeline, until the world can be weaned off fossil fuels. So what about capturing and storing the CO2 – sequestering the carbon – in the meanwhile? Trees do that, naturally, but is there a better future in locking it underground – and aren’t those vast saline aquifers the ideal place? Roger East chairs the debate.
| YES | | NO |
| Andrew Chadwick, principal geophysicist at the British Geological Survey, and one of the Sleipner sequestration experiment monitoring team | | Paul Johnston, principal scientist at the Greenpeace Research Laboratories |
Andrew Chadwick: We need to cut CO2 emissions quite drastically in the next few decades. Just to stabilise atmospheric levels (at say 450-550 parts per million) requires a reduction of 25% in the next 20-30 years, and deeper cuts of the order of 60% are necessary in the longer term. The question is, how do we achieve this? The cheapest CO2 savings come from updating old power stations, but this won’t take us far enough. Investment in renewable energy, by contrast, has high potential (offering near-zero emissions) but much higher costs. For somewhere like the UK, too, reliance on renewables raises real issues of space. How much room do we have for wind farms, and can we realistically cover the countryside with crops for biomass? Carbon sequestration is a ‘middle way’, a moderate cost response with high potential for keeping CO2 out of the atmosphere. But sequestration does not necessarily mean forestry, which isn’t a particularly secure way of storing carbon; just look at the scale of destruction of European forests in recent storms and the increasing incidence of fires. The technology I’m proposing involves collecting CO2 from our major industrial emitters and storing it in underground formations. Disused oil and gas fields are one possibility. The best option, however, is secure long-term storage in saline aquifers – vast underground rock formations, at a depth of 1-2 km beneath the earth’s surface, whose pore spaces are filled with salt water – into which we can pump CO2 instead.
Paul Johnston: Certainly we need to take action on CO2 emissions. Climate change is, unarguably, one of the major threats facing mankind and the global environment, and we should look carefully at any potential contribution to mitigation. That includes carbon storage options – some more promising than others. It’s important to distinguish between them, and I acknowledge that there seems to be real potential in saline aquifers. But we need to understand the full scope of these approaches. How can you be 100% certain that you’d be locking the gas up long term? Even very low leakage rates would negate any possible benefits. And even if it were possible to meet all the concerns about leakage, the integrity of geological formations, the impact on ecological systems within the aquifers, there’s a wider issue. These storage proposals mark a crossroads in our strategic approach. We get all concerned about cutting emissions, and then along comes a macro-engineering solution. Suddenly it’s the flavour of the month. The coal industry’s behind it, the oil industry’s behind it, geologists are behind it. Within a politician’s five-year timescale, what will people say? “CO2? We’re going to put it all down holes in the ground, we don’t need to bother with renewables any more.” But trapping, purifying and storing CO2 are all very cost-intensive. Committing to this route could mean we are precluded, financially and economically, from more sustainable solutions.
Roger East: Two big questions for you there, Andrew: will it work, and – if it does – is it still a red herring in the big picture?
AC: Will it work? Yes. We can say with a high degree of certainty that CO2, liquefied and stored in a saline aquifer with an effective seal, will remain there for geological timescales – hundreds of thousands of years, perhaps even millions. The science of how buoyant liquids behave is well understood. What’s more, where the boundary layer of CO2 comes into contact with the surrounding aquifer geology and the sealing cap rock, the ensuing chemical reactions may well be helpful, reducing permeability. Admittedly it is much more difficult to predict leakage from oilfields, where liquid CO2 may be pumped in for enhanced oil recovery (or potentially just for sequestration), because they tend to be peppered with wells. But a lot of enhanced oil recovery has been carried out, so far, with no catastrophic leakages. At Florina in Greece, a well started to leak CO2 – then, after 10 years, it self-sealed, apparently as a result of a build-up of carbonate. Remember, too, that large natural accumulations of CO2 underground have remained stable over millions of years. And, where it does leak to the earth’s surface, it’s not toxic, flammable or explosive. Locally, natural CO2 leaks have become tourist attractions, or carbonated mineral water.
PJ: Contrast that with Mammoth Mountain in California, where seepage up through the soil was found to have suffocated tree roots and produced lethal concentrations of CO2 in poorly ventilated buildings.
AC: But volcanic areas like Mammoth are precisely the kind of places you would not choose for CO2 storage.
PJ: In any case, the main issue here is not catastrophic releases from storage sites – that’s more likely when the CO2 is being transported, or in the pre-injection stages. But you might as well not bother sticking it down a hole in the ground in the first place with leakage of even fractions of 1%. Because this would mean that ultimately, it’s all going to come back out.
AC: That’s simply untrue. But just suppose we could only ensure secure storage for 500 years. Even this would get us past the point where CO2 concentrations in the atmosphere would otherwise peak – at say 900 parts per million – as a result of our fossil fuel use. Peak-shaving like that has got to be a good thing.
PJ: Ah, peak-shaving. The same argument as is being promoted for approaches such as injecting CO2 into the deep ocean. But we’d end up with a higher equilibrium situation than if we did nothing at all, simply because of the energy penalties involved in liquefying the CO2. And it violates an important precept of sustainability, that we should not be imposing constraints on future generations.
AC: The fact is that the vast majority of our energy at present comes from fossil fuels...
PJ: For which this is widely seen as a get-out-of-jail-free card...
AC: ...And the transition from fossil fuels, whether it takes 30 or 80 years, is not going to happen overnight. We have no alternative but to use fossil fuels for several more decades. CO2 sequestration enables us to dispose of a significant proportion of the consequent emissions, while we build up the huge infrastructure needed to get our energy from renewables. In my view there is no other way of doing it.
PJ: You are quite right that it is unrealistic to expect us to move to 100% renewables tomorrow. But you need to demonstrate a robust analysis of how the two strategies are going to evolve together. Make sure the one is not developed at the expense of the other. How much infrastructure would have to be built for sequestration – and how much investment would this deflect from renewables? There are other options – even the ‘do nothing’ option. And, unless you can guarantee that you are going to get the ‘peak-shaving’, you are holding out a potential false promise to people.
AC: We can, within reasonable bounds of certainty, guarantee that. Underground sequestration, we know, is technically practical. There is some minor disquiet about safety, but in my view the issues are tractable, and these techniques will keep CO2 out of the atmosphere for much longer than the 500 years required for peak-shaving.
RE: And you aren’t concerned that this could take the heat off, reduce the urgency of efforts to switch from fossil fuels to renewables, just when we need to keep the heat on?
AC: It would be a triumph if we could sequester enough CO2 to take the heat off!
PJ: I don’t have a problem with the research you are doing. This whole area of research is useful, but I do have a problem with the one-size-fits-all idea that it’s the solution. It’s really just a continuation of the ‘dilute and disperse’ philosophy. We need to ask, too, how remediable it is – and what about the impact on the ecosystems of saline aquifers if you pump them full of CO2? The bacterial microflora living there presumably fulfil some ecological function, even if we don’t understand it yet.
“CO2 stored underground is a much more benign legacy to future generations than CO2 up in the atmosphere.”
AC: CO2 stored underground is a much more benign legacy to future generations than if it’s up there in the atmosphere. As for the impact on ecosystems, we are only proposing the use of a tiny proportion of the earth’s crust. There may well be long-lived relic bacteria in sandstone aquifers, and injecting CO2 may have an impact, but in the wider context it will be very small.
PJ: We used to assume that the deep sea was barren. How likely is your assertion also to be discredited?
AC: There is some research being done. But do we balance a minor impact, on a system we know nothing of, and that may not even exist, against the consequences of increasing CO2 levels in the atmosphere? In the next few decades we have to reduce those emissions, by say 50% – but, no matter how quickly we move to renewable energy, we are going to have to burn lots of fossil fuel during that time. What are we going to do with the resultant CO2? An effective way to cut emissions is by sequestration. Underground storage is not the sole answer – all we are saying is that it’s a tool in the toolbox, but it’s a very important one.
“There’s a danger of siphoning away funds from renewables and energy efficiency.”
PJ: We need to answer a lot of questions first. One key problem is the perception that the macro-engineering techniques are all the same, whereas in fact we need to differentiate between the contained options you advocate, and uncontained options like deep-sea dispersal. They need to be shown to be separate, with different underlying attitudes – although even contained storage, if it is beneath the sea bed, may require a renegotiation of treaties on dumping at sea (which could in turn open all manner of hornets’ nests). Then we need to move from ‘proof of concept’ to a complete evaluation of the socio-economic impact in the widest sense. This means being very mindful of the impacts on renewable and energy efficiency technologies – and the danger of siphoning away funds from those solutions. And it means being quite humble, acknowledging what we don’t know – and what we don’t even know we don’t know.
PJ: I don’t have a problem with the research you are doing. This whole area of research is useful, but I do have a problem with the one-size-fits-all idea that it’s the solution. It’s really just a continuation of the ‘dilute and disperse’ philosophy. We need to ask, too, how remediable it is – and what about the impact on the ecosystems of saline aquifers if you pump them full of CO2? The bacterial microflora living there presumably fulfil some ecological function, even if we don’t understand it yet.
“CO2 stored underground is a much more benign legacy to future generations than CO2 up in the atmosphere.”
AC: CO2 stored underground is a much more benign legacy to future generations than if it’s up there in the atmosphere. As for the impact on ecosystems, we are only proposing the use of a tiny proportion of the earth’s crust. There may well be long-lived relic bacteria in sandstone aquifers, and injecting CO2 may have an impact, but in the wider context it will be very small.
PJ: We used to assume that the deep sea was barren. How likely is your assertion also to be discredited?
AC: There is some research being done. But do we balance a minor impact, on a system we know nothing of, and that may not even exist, against the consequences of increasing CO2 levels in the atmosphere? In the next few decades we have to reduce those emissions, by say 50% – but, no matter how quickly we move to renewable energy, we are going to have to burn lots of fossil fuel during that time. What are we going to do with the resultant CO2? An effective way to cut emissions is by sequestration. Underground storage is not the sole answer – all we are saying is that it’s a tool in the toolbox, but it’s a very important one.
“There’s a danger of siphoning away funds from renewables and energy efficiency.”
PJ: We need to answer a lot of questions first. One key problem is the perception that the macro-engineering techniques are all the same, whereas in fact we need to differentiate between the contained options you advocate, and uncontained options like deep-sea dispersal. They need to be shown to be separate, with different underlying attitudes – although even contained storage, if it is beneath the sea bed, may require a renegotiation of treaties on dumping at sea (which could in turn open all manner of hornets’ nests). Then we need to move from ‘proof of concept’ to a complete evaluation of the socio-economic impact in the widest sense. This means being very mindful of the impacts on renewable and energy efficiency technologies – and the danger of siphoning away funds from those solutions. And it means being quite humble, acknowledging what we don’t know – and what we don’t even know we don’t know.
RE: And you aren’t concerned that this could take the heat off, reduce the urgency of efforts to switch from fossil fuels to renewables, just when we need to keep the heat on?
AC: It would be a triumph if we could sequester enough CO2 to take the heat off!
PJ: I don’t have a problem with the research you are doing. This whole area of research is useful, but I do have a problem with the one-size-fits-all idea that it’s the solution. It’s really just a continuation of the ‘dilute and disperse’ philosophy. We need to ask, too, how remediable it is – and what about the impact on the ecosystems of saline aquifers if you pump them full of CO2? The bacterial microflora living there presumably fulfil some ecological function, even if we don’t understand it yet.
“CO2 stored underground is a much more benign legacy to future generations than CO2 up in the atmosphere.”
AC: CO2 stored underground is a much more benign legacy to future generations than if it’s up there in the atmosphere. As for the impact on ecosystems, we are only proposing the use of a tiny proportion of the earth’s crust. There may well be long-lived relic bacteria in sandstone aquifers, and injecting CO2 may have an impact, but in the wider context it will be very small.
PJ: We used to assume that the deep sea was barren. How likely is your assertion also to be discredited?
AC: There is some research being done. But do we balance a minor impact, on a system we know nothing of, and that may not even exist, against the consequences of increasing CO2 levels in the atmosphere? In the next few decades we have to reduce those emissions, by say 50% – but, no matter how quickly we move to renewable energy, we are going to have to burn lots of fossil fuel during that time. What are we going to do with the resultant CO2? An effective way to cut emissions is by sequestration. Underground storage is not the sole answer – all we are saying is that it’s a tool in the toolbox, but it’s a very important one.
“There’s a danger of siphoning away funds from renewables and energy efficiency.”
PJ: We need to answer a lot of questions first. One key problem is the perception that the macro-engineering techniques are all the same, whereas in fact we need to differentiate between the contained options you advocate, and uncontained options like deep-sea dispersal. They need to be shown to be separate, with different underlying attitudes – although even contained storage, if it is beneath the sea bed, may require a renegotiation of treaties on dumping at sea (which could in turn open all manner of hornets’ nests). Then we need to move from ‘proof of concept’ to a complete evaluation of the socio-economic impact in the widest sense. This means being very mindful of the impacts on renewable and energy efficiency technologies – and the danger of siphoning away funds from those solutions. And it means being quite humble, acknowledging what we don’t know – and what we don’t even know we don’t know.
9 June 2004
Roger East
