The Promise Of Carbon Capture For Addressing Climate Change

Speaker 1: 00:00 As president Biden and leaders around the world engage in a climate summit on this earth day. The focus is reducing carbon emissions leaders are discussing ways to slash CO2 emissions as quickly as possible to avoid a disastrous increase in global warming. But some scientists are now saying the only way to achieve a limit to global temperature rise is to pair emission reduction efforts with a massive investment in carbon capture technology, basically removing some of the existing CO2 concentrations already in the atmosphere. Joining me is Ryan Hannah he's assistant research scientist at UC San Diego lead author of a paper on the emergency deployment of direct air capture as a response to the climate crisis. And Ryan, welcome to the Speaker 2: 00:50 Program. Thanks for having the Marine. Speaker 1: 00:53 Now, I remember speaking to a climate scientists several years ago about the idea of using technology to remove carbon from the atmosphere. And at the time it was treated a little bit like science fiction. Do we have the technology now to remove CO2 from the atmosphere? Speaker 2: 01:11 We do it, it sounds like science fiction, but it's actually based in a process that is mature well-known and has been used in the oil and gas industry for, for decades. It's the process of capturing CO2 either from, from natural geologic sources or from industrial sources, um, from a high level, it's quite simple. It, it just involves using, uh, organic compounds that selectively absorb CO2 from, from gas streams. And so what you get out the back end is on the one hand, a pure CO2 stream that you can use, whether it goes to underground storage to address climate change concerns in the past, it's gone to agriculture food and beverage industries. So, so you get pure CO2 on the one hand and then a relatively depleted stream of atmosphere at gases that are mostly free of CO2 that goes back to the atmosphere. So, so the technology is absolutely there. The concerns now I think have shifted to the costs, Speaker 1: 02:15 But do we know after that carbon is extracted from the atmosphere and the idea is to safely store it under the earth, would it be safe there? Would it be safe? Speaker 2: 02:26 The planet geologists are, I think are pretty confident with underground storage. We have a lot of experience with, with injecting gases, into depleted oil and gas reservoirs. Of course, there's, there's always the chance that leakage can occur. And so there's significant monitoring. Well there, first of all, there's characterization of the geologic formations into which the, the gases are injected prior to injection, but, but then during injections, there's also extensive monitoring of the reservoir and of the plume. Once it's underground, we have experience with injections through a couple of different processes that actually the CO2 has been injected into old oil and gas reservoirs to, to, to basically increase production at the end of the, uh, reservoirs life and in a process called enhanced oil recovery. That's been, that's been happening for decades. Um, more recently with tests around dedicated storage to address climate change. Um, we have been injecting CO2 into, uh, saline reservoirs, uh, for example, in, in, in, in Illinois there there's, there's been ongoing injections and characterization for the past several years. And so I, I think the consensus amongst geologists is that, is that we're confident that that with monitoring these reservoirs can store gasses off, you know, on the timescales that matter for climate change. Speaker 1: 03:52 So you said one of the big issues right now is the money it would take. And what kind of money would it take to deploy direct air capture technology to make a significant difference in climate Speaker 2: 04:03 Change? Yeah, the, the, the short answer is we don't quite know yet because no major commercial plants has been built. We have, we have a few, a few pilot plants and those give us some initial numbers that could be indicative of what larger in fact much larger plants might do. But the reality is we simply don't know, even at very high costs of storing CO2 through carbon capture and direct air capture. What we do know is that the climate modeling and the energy systems modeling that's, the IPC carries out, shows us that having these options, even at a very high costs reduces the overall cost of the de-carbonization challenge in the long run. So Speaker 1: 04:48 If I understand you correctly, what you're saying is that the cost of direct air capture of taking CO2 out of the air would be cost effective because the cost of reducing emissions alone to try to achieve the same level of carbon reduction would be more expensive. Is that right? Speaker 2: 05:11 That's absolutely right. One way to think about direct air capture and other, uh, technology is what we call negative emissions technologies that actually reduce CO2 out of the atmosphere is, is that they act as, as a backstop against all of the conventional mitigation that needs to happen in all of the economic sectors. So in, in, in for any economic sector, one can look at the cost of decarbonizing that sector. So for example, cement production or steel production, which are very hard to decarbonize or aviation, for example, for which we don't really know what the solutions are going to be and what their costs are going to be. We, we, we can't on the other hand, look to these negative emissions technologies as a backstop and say, well, if the negative emissions technologies are cheaper or appear to be less costly than going into the sector and decarbonizing it, then it would make sense to preferentially go with the negative emissions options. Instead for simply from a cost perspective, Speaker 1: 06:05 How much carbon could these negative emissions options take out of the atmosphere? Speaker 2: 06:12 In theory, I could do quite a lot, the intergovernmental panel on climate change, which is the main international body that does all of the, the modeling and scenario work that kind of tells us, um, how, how quickly we need to reduce emissions overall tells us that we will need something on the order of 200, to a thousand gigatons of CO2 removed from the atmosphere. That's on the order of, at the low end five to six years of, of global emissions on the high end 20 to 25 years of global emissions over the century. And so we know there's absolutely a need for these, for these different means of negative emissions. Um, and really the sky is the limit for them Speaker 1: 06:56 Is not the whole solution, right? We still need to decrease our emissions Speaker 2: 07:01 100%. There's no way around that. Conventional mitigation actually getting the emissions out of the economic sectors in addition to negative emissions, those need to be seen as compliments. Speaker 1: 07:11 So what are our CO2 levels now in relation to the goals set by the Paris accord? I think they were hoping to limit warming to about one and a half degrees centigrade. Where are we now Speaker 2: 07:22 Right now? Uh, because of the inertia of the climate system with our existing emissions baked in about one degree centigrade of, of warming already. And that's obviously set to increase the best estimates that we have for, for warming based on sort of where we are now and where we think we're going to go in, in the future with emissions, given current policies that puts us on track for something like three degrees of warming by the end of the century. So that's, that's obviously too high and dangerous. And so the challenge to, to stop that as is, is immense, as we know, every month or, or year of delay in addressing climate change, really just compounds the challenge because we've let more emissions into the atmosphere, which means the task of taking those out later becomes greater. What does it mean? Speaker 1: 08:18 I mean, if we go higher than that one degree up to even the three degrees that you mentioned, what does that mean to life on earth? Speaker 2: 08:24 I think the important way to think about global warming is that every increments or incremental degree is worse than the increment before it. And so it's a spectrum, you know, wifi on earth, doesn't cease at 1.6 degrees where it exists at 1.4 and the same is true at two degrees and three degrees, rather the damages and the effects to human civilization are worsened with each incremental degree. And so the way that we think about the thresholds is, uh, as a target, as a way to, to sort of focus the mind, but the damages of course are continuous rather than say, binary or discrete as Speaker 1: 09:10 Temperatures rise. What changes would Speaker 2: 09:12 We see? I think a few of the major changes involve warming in the Arctic and the poles, especially which you see drastically higher impacts than the rest of the, uh, the earth to warming. So, so certainly glacial melts at the polls, uh, ice cabinets at the polls, thawing of permafrost, think to, to human systems, the warming adds to potential threats of my migration and movement of different peoples due to the, to the additional warming and to the effects that come with that. And that affects for example, their, their livelihoods, whether that's has to do with crops or water availability. Speaker 1: 09:59 I have hope that this week climate summit will address the subject of direct air capture and maybe move that idea forward. Speaker 2: 10:07 I think the idea has, has come into the mainstream scientifically. It's hard for me to say whether it's in the mainstream publicly, but I think the idea that negative emissions are critical to the solution is now I think, well, well accepted and various various groups, whether they're scientists in labs or whether they're NGOs or think tanks are calling for massive government investment in these technologies. And so I do have hope that these efforts into improving, improving out the potential for these negative emissions technologies will emerge over the next decade. Speaker 1: 10:46 I've been speaking with Ryan Hannah and assistant research scientist at UC San Diego. Ryan, thank you very much. Speaker 2: 10:53 Thanks for having me on bring in celebration Speaker 1: 10:55 Of this week's earth day. I love a clean San Diego is hosting an all day cleanup on Saturday. You can choose a block, a park beach, Canyon, or neighborhood near you and remove trash to make sure it doesn't end up in our ocean to register, go to Creek two bay.org.