As California burns, oceans rise, storms intensify, and Greenland’s glaciers melt, the world continues to try to identify solutions to the ongoing climate crisis. Mark Jacobson has conducted a new study on the impacts of carbon capture and direct air capture. Are these solutions viable? What are the health and climate impacts? Maria Armoudian spoke with Jacobson about his latest research.

Mark Jacobson is a Professor of Civil and Environmental Engineering at Stanford University. He is an expert in environmental engineering and renewable energy solutions and is the author of Air Pollution and Global Warming History, Science, and Solutions.


This interview has been edited for clarity and length 

Maria Armoudian: Given what is going on environmentally right now, how urgent is it to act quickly on climate change?

Mark Jacobson: It is very urgent that we act now to transition the entire world’s energy infrastructure to entirely clean renewable energy to the extent we can. This means electricity, transportation, and the heating industries. We need to transition as fast as possible to eliminate all combustion emissions and that includes fossil fuels and biofuels.

MA: Do you know what happened where scientists seemed to have underestimated the speed with which the climate has been changing now? It sounds like they are saying they were off and it is getting worse a lot faster than they predicted. What happened?

MJ: There are some camps of scientists that felt there was an urgency and that things were getting bad rapidly and then there were others who were slower and others who thought there was not a problem at all. So I think what you are saying is really the fact that we have been struggling with a lot of people who have been denying climate change dominating the conversation and as a result, nothing was getting done. And now we are seeing some of these impacts that people have been talking about for a while coming to fruition and now we have to face reality. So it was something that was always cooking in the system. I think the problem is a lot worse than we think and the reason is because air pollution which kills seven million people per year globally also masks about half of global warming. So as we clean up our air pollution, we are going to uncover rapidly even more warming, warming that people don’t even see because of pollution particles which reflect light and cool the surface air. So these pollution particles have been masking about half of global warming and now as you start cleaning up pollution particles you are going to see this unmasking and faster warming.

MA: So you are saying that as we make the switch to renewable energies and we are not putting more pollution into the air that simultaneously we have to deal with those emissions that have been masked?

MJ: It is a little bit more complicated because some of those pollution particles cause warming, most of them cause cooling, but some of them cause warming and we want to eliminate both because of the health effects. But at the same time, there is invisible carbon dioxide which causes warming as well and also other greenhouse gases, nitrous oxide, methane, these all cause warming. We need to reduce not only CO2 but the other gases as well simultaneously. So as we reduce the air pollutants that cause health problems we also need to be reducing greenhouse gases, so we will be causing some warming due to the reduction of the cooling particles.

MA: Can you give us another reminder of your work from ten years ago and what your outcomes were with regards to renewables, as well as any update on that?

MJ: So in 2009 I did a study looking at what were the best technologies being proposed to address global warming, air pollution, and energy security. And these included wind power, solar power, geothermal power, wave power, hydroelectric power. Those I called wind, water, solar options. But in addition to those, people have been proposing nuclear power, coal carbon capture, and natural gas with carbon capture which is where you try to extract carbon dioxide from power plant emissions, and also biofuels.

So I evaluated all these technologies in terms of their health impacts, their climate impacts, their impacts on land, water, security risks, materials, etc. I ranked all these and found that the wind, water, and solar options were the best in terms of trying to solve the problem of climate change, air pollution, and energy security simultaneously, whereas nuclear power, coal carbon capture, and biofuels were not so good. It doesn’t mean some of them were better than fossil fuels on their own they just were not as good as the wind, water, and solar options. And I got attacked quite a bit for that mostly by people in the industries.

It has been proven since then that nuclear power is way too expensive, it is four to five times more costly than wind and solar energy right now and takes about five to seventeen years longer to implement. In addition to this, there is meltdown risk, weapons proliferation risks, waste issues, mining issues, so that is pretty much off the table in terms of a solution to global warming. Biofuels, although they are still around, most people see that they cause air pollution because you still burn them and they still contribute to global warming, so that is not a good solution.

Finally, carbon capture, which is where the carbon dioxide from a power plant or from some industrial process is captured by some equipment, usually there is no financial benefit from this so the companies that are doing this these days are taking up CO2 and selling it and the only people who are buying it are oil companies. And the CO2 where this is being done is being piped to oil wells where it is being pumped into the wells and reduced in density so the oil can come to the surface faster. And so you might say well how does that help the climate if you are just getting more oil to burn?

In fact, it doesn’t, because not only that but about half of that CO2 leaks somewhere along the line so we don’t even know how much CO2 stays captured and it just increases oil consumption and combustion. This is being proposed as a solution to global warming and I just did a study quantifying the actual emissions associated with carbon capture from an existing plant in Texas where capture equipment was put on an existing coal plant at a cost of one billion dollars. And I looked at the data and it turns out you need a lot of energy to power this capture equipment, so they built a natural gas plant just to run the carbon capture equipment for the coal plant. And not only that, none of the carbon dioxide from the natural gas plant is captured, it is just released to the air. People have claimed that the carbon capture equipment reduces about ninety percent of carbon dioxide from the coal plant, but in fact, when you actually look at the data and you capture all the upstream emissions and the combustion emissions from the natural gas and the coal, you find that over a twenty-year timeframe only about ten and a half to eleven percent of the carbon equivalent emissions are captured, the rest is released to the air. Remember this is for one billion dollars and yet, you hardly capture any carbon dioxide.

I looked at this case, and I thought okay you could probably make this better by using a wind turbine instead of the natural gas to power the capture equipment. If you do that, you do reduce the emissions associated with natural gas, but then you could just use the wind turbine to replace the coal in the first place. It turns out if you do that you don’t need to buy the capture equipment and you eliminate all the air pollution associated with the coal, you eliminate the mining, the infrastructure associated with the coal.

Whereas the carbon capture equipment, it doesn’t reduce any pollution from the coal, it costs money, it doesn’t reduce mining. So I looked and found that any investment, even in wind power for carbon capture increases carbon dioxide, increases air pollution, increases total costs relative to using that same wind just to replace the coal in the first place. There are zero benefits to carbon capture at all, it is always better to take that same energy that you are using for capture equipment and replace the coal and the gas, you are always going to get a better benefit.

MA: One of the arguments you started to address was about reusing that carbon for something and right now you said it was only fossil fuels that were using it. But the proponents of carbon capture have argued that you can also use it for medicine and for biodegradable plastics. Is there any validity to that?

MJ: Well, you can use carbon dioxide for a lot of things, but there are more efficient ways to get carbon dioxide than this. For example, trapping methane from a landfill, you don’t need carbon capture equipment as the natural gas is already quite isolated. So then you take the natural gas, and you use it in a fuel cell to produce hydrogen and then that hydrogen can be used for transportation. Now the product of natural gas going through a fuel cell to produce hydrogen is carbon dioxide, so there you have a stream of carbon dioxide that can be used for all those purposes. But you don’t need the carbon capture equipment for that and you are also producing hydrogen that you will need anyway which will otherwise be produced from cleaner renewable energy anyway.

So here is a way to take some waste that is going to go to the air anyway that is eighty-four times more powerful than CO2 which you can convert into useful products as opposed to trying to keep this coal plant alive. This has zero emissions associated with it and zero energy, whereas using carbon capture at a coal plant to try to capture carbon that doesn’t reduce any air pollution and allows the whole coal system to continue, in fact, it makes it even easier to use more coal and more natural gas.

MA: You talked about the best carbon capture methods are the ones provided by nature such as trees. What can you tell us about the idea of planting trees as a means of carbon capture in contrast to trying to do it this other way?

MJ: The first step is replacing fossil fuels with renewables which is the exact same thing as carbon capture because by preventing carbon dioxide from getting into the air that is like taking one molecule out of the air. So the first step is to stop the emissions, and that is replacing all fossil fuels with cleaner renewable alternatives. For pretty much everything right now there is an alternative that doesn’t result in any emissions. And then after that, to take some carbon out of the air planting trees helps, we don’t need to cover the planet with trees we need to increase the reduction of CO2 from the air. It is not only planting trees, but it is also avoiding permanent deforestation, we can put policies in place around the world to reduce the tree loss due to permanent deforestation.

Permanent deforestation is where you burn down part of the Amazon, for example, to convert these very dense forests into cattle grazing land, this is where you change the land use permanently as opposed to temporary deforestation where there are things like a forest fire and it regrows. Of course, big trees will take eighty years to regrow, so it is not an immediate regrowth. So if we can reduce biomass burning, that can go a long way towards effectively planting trees. But there are other things we have to do to reduce warming and that is to reduce things like nitrous oxide emissions, methane emissions, and other sources, so there are other things that are low-hanging fruit that we can also try to reduce that don’t require this capture equipment. The capture equipment is literally the worst thing to use because it requires extra energy and it doesn’t reduce any other pollutants.

MA: You and your colleagues have been working with cities, states, countries and have written a bunch of reports about how to go to 100% renewables by 2050. Isn’t 2050 perhaps a little slow now given what we are seeing?

MJ: Well, all our plans have been to go to eighty percent renewables by 2030 and the last twenty percent somewhere between 2030 and 2050. So you are right, if we all of a sudden did it in 2050 it would be too late but our goals are very aggressive trying to get to eighty percent by 2030, and that in fact is more aggressive than any inter-governmental panel on a climate change target. They basically have like forty percent by 2030 at the most. But eighty percent I think we can avoid 1.5-degree global warming with that transition if we can do it worldwide not only for all energy but also all other emissions.

MA: Can you give some examples of how some states or some countries can do this and do this quickly?

MJ: Well, the idea is to electrify everything and provide the electricity with renewable energy. So transportation we go to electric vehicles, for buildings we go to heat pumps for both air heating and air cooling and water heating and water cooling, and then for industry we would use electric high-temperature industrial processes. Then we provide all the electricity with clean renewable energy like wind, water, solar power. People can do this in their own homes; I mean you can think, “What do I have that burns a fossil fuel?” You might have a gas stove so instead of using that you would then get an electric stove, or you might have a gas water heater so go to a heat pump instead, you might have a gas car, go to an electric car.

And then you can also make your house more efficient with energy-efficient lightbulbs and things, basically, try to electrify your home. This is the same thing any building can do. There are now a few hundred international companies that have committed to one hundred percent clean renewable electricity for their global operations, companies are now realising this is an important goal. Worldwide there are over 230 cities that have made similar commitments and there are 61 countries that have committed to one hundred percent renewable electricity worldwide, however, electricity is not enough –  we also have to transform transportation, building heating and cooling, and industry.

MA: And states in the US, I know California is working on it, Virginia has made a big commitment.

MJ: There are nine states plus the District of Columbia and Puerto Rico who have all committed to one hundred percent renewable electricity between 2032 and 2050. Again they haven’t committed to this in other sectors, but it is a start. California has done this but also states like Virginia, Hawaii, Washington, Maine, Wisconsin, New York, and New Mexico. California right now is at about fifty-five percent clean renewable energy so in other words fifty-five percent of all California’s electricity is generated by either solar, wind, or hydro-electric power and geothermal power right now. I think California will actually get to seventy percent by 2020 and maybe to one hundred percent by 2030.

MA: Do you have a sense if all of these movements to power one hundred percent from renewables is enough to counter the backward steps of people like Trump and Bolsonaro?

MJ: Yeah, in fact, part of the passing of the laws has been a reaction to the Federal Government not taking any action. The thing is, communities, individuals, counties, and states can do a lot. I mean they don’t necessarily need the Federal Government in a place like the US to solve the problem. Of course, the Federal Government will help solve the problem and is providing tax incentives which is what is driving a lot of the transition, a Federal tax credit. So the Federal Government can speed it up, but it can also slow it down by preventing permits for certain things and not giving incentives. But despite what the Federal Government here is doing there has been a lot of action, in fact, coal has been dropping as a result of all this action.

So when Trump was elected, I think coal was producing around forty-two percent of US electricity, now it is around twenty-five percent and several coal companies are going bankrupt. It is not because of policies, just the economics of wind and solar mass production have driven prices up so much that coal cannot compete. The nice thing about renewables is they have no fuel costs, wind comes right to the turbine, solar comes right to the panel, there is no fuel costs whereas coal and gas you always have to dig it up, in fact in the US there are 50,000 new oil and gas wells drilled every year just to dig up these fossil fuels. So that means their prices and costs are going to stay high, they are never going to come really low like wind and solar are.

MA: So a lot of the naysayers argue that China and India are mass polluters and emitters, but China is embarking on renewables at a fairly rapid rate, aren’t they?

MJ: Yeah, I mean they are producing more solar and wind than most other countries. Even though compared to the size of their energy it is not a huge percent yet. But they are doing a lot and they can do more. They are also doing things in transportation, they are electrifying buses by the tens of thousands, starting to get into electric aircraft because they have huge air pollution problems, I mean, seven million people die per year from air pollution and maybe between one and one and a half million of them are in China. So this is a country that is trying to preserve itself by electrifying and cleaning up the air. The US has cleaned up a lot of its air pollution, but it still has a lot in places like LA, in fact, seven of the ten most polluted cities in the US are in California. So there is actually motivation in California to clean up the air and also in other states. But China has in order of magnitude much higher pollution, they are making progress but to self-preserve themselves.

MA: I suppose the other area that has been criticised for doing renewables is energy storage both because of times when you might not have the sun or wind, but also with electrified transportation as well. How are we advancing technology with storage? Are there advances that are promising?

MJ: Well, there is storage in not only electricity, but there is heat storage, coal storage, and hydrogen storage. And heat storage and coal storage are relatively inexpensive, hydrogen storage is cheap as well. But there are certain types of electricity storage that are not that expensive like hydro-electric power is basically a big battery, concentrated solar power storage is not very much. It is mostly batteries that are the expensive electricity storage but those have been coming down and there are different types of battery that are being developed as well, there is gravitational storage that is not that expensive, then there is also compressed air storage which is new technology with potential but it is really new.

MA: Do you have a sense that these new technologies are going to provide solutions for intermittence we might be facing in the future if we do go to one hundred percent renewables globally?

MJ: Well right now battery storage with solar or wind is very cheap. Now, this is storage on the order of hours to days; it is not like months’ storage, so that reduces the fluctuations in renewables. But it is really cheap, I mean we are talking three cents a kilowatt for the combination of solar plus batteries and that compares with six cents per kilowatt for natural gas. Solar plus battery is beating out natural gas right now, same with wind plus batteries. People are concerned about how we are going to get all the electricity we will need in the wintertime when we need a lot of heating. If we electrify the heating it turns out if you use a heat pump you are using one forth the energy as you do with gas heaters. So you don’t need as much electricity in the winter as you do gas in the winter if you use electric heat pumps. So you can mitigate the impacts of seasonal variation of demand by the fact you have less demand for energy when you electrify. If you electrify everything your power demand goes down about fifty-seven percent for all sectors so that does help to match power supply with demand on a feasible timescale.

MA: Speaking of batteries, that has been one of the criticisms on electrifying transportation, battery disposal, is that a legitimate concern?

MJ: Well lithium itself is not a toxic metal. I mean there are other materials in batteries that are toxic, but the idea is to recycle batteries to the extent that they can. So companies like Tesla have battery recycling programs and I think going forward that is the way to go in terms of recycling all the materials as much as possible. Keep in mind that if a battery lasts ten years, the worst case is it is like a one-time mining and disposal situation, whereas when you have fossil fuels you have continuous mining forever and continuous use and continuous disposal and that disposal is in our air and we are breathing it in our lungs. So these fossil fuel companies are disposing of their waste in our lungs, whereas in a worst-case scenario of battery disposal even if it didn’t get recycled there is nothing near the order of magnitude of waste that results from the fossil fuel industry.

MA: Any other technologies you see coming online that are going to help us move to this goal of one hundred percent renewables?

MJ: I think the most difficult thing to change is long-distance heavy transportation, aircraft in particular. New aircraft are available that are electric that can go up to 1500 kilometres but we need technologies for further than 1500 kilometres, up to ten thousand kilometres. For those we would use hydrogen fuel cells and those technologies have not been developed, but they are theoretically possible and so we expect within the next fifteen to twenty years long-distance heavy transport, but right now we don’t have it. That is one of the very few types of technologies that are not currently available to transition but I would say we have ninety-five percent of the technologies we need for the transition and the rest are technically possible. We just haven’t commercialised them yet.

This interview was originally aired on the Scholars’ Circle. To access our archive of episodes and download this interview click here.

The Scholars’ Circle is our radio show that is broadcast weekly in ten US cities and available via podcast and/or transcript on our website. It brings together scholars’ from across various disciplines to discuss current issues in their chosen fields and various research that is taking place. For more click here.

See Also:

Q+A: 100% global renewable energy: Is it possible?

Q+A: Do we need to radically change our lives to stop climate change?