[MUSIC] George, thanks very much for the talk. I'd, I'd like to follow up with a few questions to see if we could clarify a fewthings. >> Sure. >> You know, for our students. So you showed a pretty big list ofpotential energy options. But then you dismissed some of them with a statement that these don't meet ourthreshold. So if that threshold is just scale, can'twe use some of these for a local solution even if they don'tscale to maybe meet world demand? >> Certainly. Some of the technologies that I discussed at the beginning don't scale to globaldemand. Using the metrics I talked about in thelecture. But locally, they in, in certain regionsof the world where the geography is, is right, they do work for example, tidalpower or convention geothermal power. There are regions around the world likehere in California for example. Geothermal is cost competitive andtechnology works and we have deployed it already. Similarly, those other technologies can'tbe deployed in, in regions that are blessed with the right geographyto meet local demand. The point I was trying to make is don'tthink that you can then extrapolate from that local solution because thegeography is right, to something that would scaleglobally. That's the point. >> Right. Got it. Alright, good. So, in, in talking about that, some of these technologies are going to have to goto very large scale in order to gain the economiesof scale that will make them competitive withfossil fuel. So, I guess the, the question is sincesome of these are not you know, tried and truetechnologies yet. Some are, wind and solar seem to be doingpretty good. They're off on their own. >> Mm-hm. >> But certainly bio fuels and severaldoes one's own. How do we support those early on, to givethem the opportunity to get to a scale where theycan be competitive? Is there a, sort of an engineering answerto that? >> Well I think we human beings need torecognize how important having adequate energysupplies are to our future. And we also need to recognize that we needto make this transition away from carbon basedfuels to to cleaner energy sources. And we also need to recognize that technologies naturally go through adevelopment stage from basic research into the developmentof a potential product out of that basicresearch. That development effort then germinatesinto a product that can be tried to introduce into the marketplace on a deploying, basically deployed in themarket and only at that point can you then find outdoes it really compete in the marketplace and, and they have togo through that evolutionary process. And so we need to recognize that, that isimportant to us as a species. And provide the right kind of supportmechanisms to allow that to happen. >> So, support them at many differentparts of their sort of development phase. >> Through that whole development chain. >> Right. >> And that requires not just long term basic research, but also productdevelopment, deployment, test marketing. And so it's a partnership between publiclong term public support for basic research and privatesector investment for profit. >> Right. So you showed an interesting slide thathad a wedge that resulted, for a newtechnology wedge that resulted in a reduction of 25 gigatons of carbon, over the next fiftyyears. Can we also have wedges on the efficiencyside? Meaning, you know, we add more efficiencyyear over year, over a baseline and that ultimately results ina significant reduction over time. >> Certainly, yes, and the analysis that Isummarized actually already assumes that record efficiencyimprovements are already going to take place. They're basically assuming that theimprovements in energy efficiency are roughly double of what they havehistorically been. And if you, if that doesn't happen, thenthe situation is even more difficult. >> Okay. So, we, we'd better increase ourefficiency and add those other wedges on top of it. >> And look for new sources. >> Okay. So, some of the solutions, to me, seemmuch more, I would say, approachable, or maybe even easy toachieve than some of the other ones. For example, the 2-3 fold increase in vehicle efficiencies that you mentioned,that seems pretty easy to achieve, we just swap ourSUVs for hybrids and we're there. You know, why don't we demand that sort ofimmediately, why isn't that something we just immediately deploytoday and make that the law? >> Well, the, part of that gets into politics and economics that's outside ofmy expertise, but certainly the improvements intransportation efficiency that I discussed, for example, are already ontheir way. In this country over the last few years,we've passed requirements that fuel efficiencystandards be increased substantially so that by the mid 2020s new vehicles are havingfuel mileages that are roughly the figures that I showedin the talk. The Europeans already essentially meetthose standards. And so, we're in some ways on our way insome of those efficiency improvements. I would just point out, replacing vehiclestock takes, you know, 15 to 20 year process. >> 20 years. >> But that's the lifetime of a vehicle. >> Right. Okay, so along that same line, if, if, youmentioned, you know, the swapping of natural gas for coal, and that thatresults in almost a 50% reduction in greenhousegas. So again, why isn't this something that,that is, you know, sort of just universallydone today? >> Well, it sounds great in principle, thetrick is putting it into practice on therequired scale. In order to to meet, to replace coal fired power plants with natural gas fueledpower plants. You gotta make sure that you have anadequate supply of natural gas, a demand for some reasonable periodof time, into the future. In this country, with the advent ofhydraulic factoring or fracking as the, some callit. That is actually happening in UnitedStates and if you look at US CO2 emissions over the last severalyears, they are actually falling. In part because of the economic crisis,but also because of the replacement of coal withnatural gas. In other regions of the world, they'relooking at whether they want to adopt thattechnology. Some countries in Europe have made anexplicit choice not to do so. And other countries like China areconsidering doing it. So that may actually happen over the nextdecade or so. >> Okay, so at least there are some brightspots, maybe, there on in, on the horizon. >> It depends on what people choose to do,but the technology is there. >> Okay, so, so, so bringing up choice, for carbon captured in storage, or, ormaybe any of the technologies that can reduceemission reductions, or that are intended to reduceemission reductions. It seems to me that a carbon tax would goa long way to sort of, giving an incentive to reach those things,and maybe even in paying for some of those. You know, from, from an engineeringperspective, you know, is this something that, that needs to beincorporated? >> I don't know if this is an engineering perspective or not, but certainly I thinkthat with carbon emissions from fossil fuels, there arelarge external costs which are not borne by, directly by thoseenergy sources. And then essentially you get a sort of afree ride from, from that perspective. And so I, personally, think it does makesense to try to level the playing field,essentially to make them, impose a cost on those energy technologiesthat is commensurate with the costs that the rest of us bearexternally. That sort of levels the playing field, I'mnot sure it makes sense to give indefinite permanent subsidies to emergingtechnologies, because that just sort of freezes in their current state ofdevelopment. >> Yeah. >> So, but certainly im, imposing costs totry to take into account external costs is tomake sense to me. >> So put a high enough cost on CO2reduction, and then let the engineering solutions that can mostefficiently address that sort of rise to the top. >> I think so, I think another idea that's worth considering is, that sort of a, acarbon tax in general should be probably sort ofrelatively neutral in terms of it's impact on theeconomy. But we also need to recognize the need foressentially developing new basic ideas to feed intothe development chain. And so that's maybe a role where thosekinds of revenues could also be used, to support that kind of longterm basic research. >> Okay. So of all the solutions you presentedtoday, which do you think have the best short term potential to make adifference, and then what technologies do you see maybe looking out 20 or even 30years that, that might actually be game changers to, togive us a chance for a? >> I think the near term, efficiencyimprovements are the obvious things to go after and, and weare, but we, we ought to look for every single opportunity to squeeze efficiencies out ofhow we use energy. We also need to recognize, however, thatthere's several billion people in the world who, you know, having a moreefficient light bulb may not be the answer to them, becausethey're not using any electricity right now, but they willin the next few decades. So the efficiency is one. I think that placing dirtier fossil fuelswith cleaner fossil fuel, that is coal for natural gas, as probably somethingthat's going to happen over the next decade or so on a wider scale, andthen looking farther into the future I think things like alternative liquidfuels bio fuels or synth fuels. May move into the marketplace. We may electrify, at least in part, ourtransportation network. So we use much less liquid fuels. And I also think that next generation nuclear technologies, probably on thecouple decade time scale may may come onto the horizon,and could also be a significant player. >> Alright. Thanks again for your talk, and best ofluck in your research. >> Thank you.