Toyota to offer rides in SAE Level-4 automated vehicles on public roads in Japan next summer
MIT engineers develop efficient means of carbon capture using electrochemical cell

Stanford study finds current carbon capture technology inefficient & increases air pollution

A study by Mark Z. Jacobson, professor of civil and environmental engineering at Stanford University, suggests that carbon capture technologies are inefficient and increase air pollution. His open-access paper is published in the journal Energy and Environmental Science.

All sorts of scenarios have been developed under the assumption that carbon capture actually reduces substantial amounts of carbon. However, this research finds that it reduces only a small fraction of carbon emissions, and it usually increases air pollution. Even if you have 100 percent capture from the capture equipment, it is still worse, from a social cost perspective, than replacing a coal or gas plant with a wind farm because carbon capture never reduces air pollution and always has a capture equipment cost. Wind replacing fossil fuels always reduces air pollution and never has a capture equipment cost.

—Mark Jacobson

Jacobson, who is also a senior fellow at the Stanford Woods Institute for the Environment, examined public data from a coal with carbon capture and use (CCU) plant and a synthetic direct air carbon capture and use (SDACCU) plant for the equipment’s ability, alone, to reduce CO2. In both plants, natural gas turbines power the equipment.

He calculated the net CO2 reduction and total cost of the carbon capture process in each case, accounting for the electricity needed to run the carbon capture equipment, the combustion and upstream emissions resulting from that electricity, and, in the case of the coal plant, its upstream emissions.

(Upstream emissions are emissions, including from leaks and combustion, from mining and transporting a fuel such as coal or natural gas.)

This research also looked at the social cost of carbon capture—including air pollution, potential health problems, economic costs and overall contributions to climate change—and concluded that those are always similar to or higher than operating a fossil fuel plant without carbon capture and higher than not capturing carbon from the air at all.

Jacobson examined several scenarios to determine the actual and possible efficiencies of these two kinds of plants, including what would happen if the carbon capture technologies were run with renewable electricity rather than natural gas, and if the same amount of renewable electricity required to run the equipment were instead used to replace coal plant electricity.

While the standard estimate for the efficiency of carbon capture technologies is 85-90%, neither of these plants met that expectation. Even without accounting for upstream emissions, the equipment associated with the coal plant was only 55.4% efficient over 6 months, on average.

With the upstream emissions included, Jacobson found that, on average over 20 years, the equipment captured only 10-11% of the total carbon dioxide equivalent emissions that it and the coal plant contributed.

The air capture plant was also only 10-11% efficient, on average over 20 years, once Jacobson took into consideration its upstream emissions and the uncaptured and upstream emissions that came from operating the plant on natural gas.

Due to the high energy needs of carbon capture equipment, Jacobson concluded that the social cost of coal with carbon capture powered by natural gas was about 24% higher, over 20 years, than the coal without carbon capture.

If the natural gas at that same plant were replaced with wind power, the social cost would still exceed that of doing nothing. Only when wind replaced coal itself did social costs decrease.

For both types of plants this suggests that, even if carbon capture equipment is able to capture 100% of the carbon it is designed to offset, the cost of manufacturing and running the equipment plus the cost of the air pollution it continues to allow or increases makes it less efficient than using those same resources to create renewable energy plants replacing coal or gas directly.

Not only does carbon capture hardly work at existing plants, but there’s no way it can actually improve to be better than replacing coal or gas with wind or solar directly. The latter will always be better, no matter what, in terms of the social cost. You can’t just ignore health costs or climate costs.

There is a lot of reliance on carbon capture in theoretical modeling, and by focusing on that as even a possibility, that diverts resources away from real solutions. It gives people hope that you can keep fossil fuel power plants alive. It delays action. In fact, carbon capture and direct air capture are always opportunity costs.

—Mark Jacobson


  • Mark Z. Jacobson (2019) “The Health and Climate Impacts of Carbon Capture and Direct Air Capture” Energy Environ. Sci. doi: 10.1039/C9EE02709B



air capture plant...
We don't need air carbon capture,
we have tons per second from power plants,
just store it then use it.

Daniel Williams

I think his 'WWS' (water wind sun) paper was a bit of a fantasy. It doesn't go into enough detail. He then tried to bring a lawsuit against the 21 scientists who debunked it.

I believe the US can and possibly will get close to decarbonising by 2050, I just don't necessarily agree with his precise methodology.

Pre-combustion natural gas CCS via SMR (e.g.: hydrogen) is about 90-95% emissions-free. More modern ATR or combined reformers are over 95% emissions-free. There is no point in post-combustion CCS.

There is no alternative to CCS for industry (such as cement, ammonia and chemicals) because these industries emit process emissions that cannot be avoided; and this is a large source of emissions.

To be honest I agree with some of what he says. Having just read again about it; he believes in hydrogen and I think this is a big step forward, even over many mainstream thinkers. Its just things like 'increasing hydro-electric (dams) 15-fold' is not that practical. There are droughts etc.

I think we will need a lot of both green (renewables-based) and blue (decarbonised natural gas) depending on the geography. And 60% electrification, which is generally accepted as the maximum in most realistic scenarios (up from about 20% today). Electricity infrastructure and storage is the main issue.


While it's fairly obvious that trying to use post-combustion CCS on coal is doing things about the hardest way possible, if Mark Z. Jacobson said that the sky was blue I would go to the window and check for myself.  After his massive lies in the "Roadmap", it's best not to listen to him at all and save the effort of sifting the facts out of the crap.

That said, there's also a new contender for CO2 capture coming in at 1 GJ(e)/metric ton.  Coal combustion emits around 210 pounds (97.5 kg) of CO2 per million BTU.  One million BTU through a coal plant at 42% efficiency generates 123 kWh.  At 1 GJ (277.8 kWh) per ton, it would take only a bit over 20% of the plant output to sop up all of its CO2 output.  Best of all, atmospheric CO2 capture systems could make an excellent "dump load" for excess generation from wind farms and PV panels and eliminate the "need" to turn down always-on nuclear plants to "make room" for "renewables".

A Facebook User

Well said Engineer-Poet. This Jacobson guy does not appear to be very credible. He was condemning the MIT carbon capture method because "it did not address coal power generation"! First off, in the developed world, coal is phasing out fast. Will he turn his ire towards China or India? Of course not -- they are too 'marginalized'. I will check his Roadmap stuff. Instead of celebrating the new discovery, he was condemning them for not addressing cows belching CH4!

Not sure why Green Car Congress gives so much coverage to Mark Jacobson and his radical activist ideas.

The comments to this entry are closed.