At current rates of greenhouse-gas emissions, the world could lock in 1.5 ˚C of warming as soon as 2021, an analysis by the website Carbon Brief has found. We’re on track to blow the carbon budget for 2 ˚C by 2036.

Amid this daunting climate math, many researchers argue that capturing carbon dioxide from power plants, factories, and the air will have to play a big part in any realistic efforts to limit the dangers of global warming.

If it can be done economically, carbon capture and storage (CCS) offers the world additional flexibility and time to make the leap to cleaner systems. It means we can retrofit, rather than replace, vast parts of the global energy infrastructure. And once we reach disastrous levels of warming, so-called direct air capture offers one of the only ways to dig our way out of trouble, since carbon dioxide otherwise stays in the atmosphere for thousands of years.

Julio Friedmann has emerged as one of the most ardent advocates of these technologies. He oversaw research and development efforts on clean coal and carbon capture at the US Department of Energy’s Office of Fossil Energy under the last administration. Among other roles, he’s now working with or advising the Global CCS Institute, the Energy Futures Initiative, and Climeworks, a Switzerland-based company already building pilot plants that pull carbon dioxide from the air.

In an interview with MIT Technology Review, Friedmann argues that the technology is approaching a tipping point: a growing number of projects demonstrate that it works in the real world, and that it is becoming more reliable and affordable. He adds that the boosted US tax credit for capturing and storing carbon, passed in the form of the Future Act as part of the federal budget earlier this year, will push forward many more projects and help create new markets for products derived from carbon dioxide (see “The carbon-capture era may finally be starting”).

Listen to more of the interview here (intro music: "Glenn" by Anitek):

But serious challenges remain. Even with the tax credit, companies will incur steep costs by adding carbon capture systems to existing power plants. And a widely cited 2011 study, coauthored by MIT researcher Howard Herzog, found that direct air capture will require vast amounts of energy and cost 10 times as much as scrubbing carbon from power plants.

(This interview has been edited for length and clarity.)

In late February, you wrote a Medium post saying that with the passage of the increased tax credit for carbon capture and storage, we’ve “launched the climate counter-strike.” Why is that a big deal?

Department of Energy

It actually sets a price on carbon formally. It says you should get paid to not emit carbon dioxide, and you should get paid somewhere between $35 a ton and $50 a ton. So that is already a massive change. In addition to that, it says you can do one of three things: you can store CO2, you can use it for enhanced oil recovery, or you can turn it into stuff. Fundamentally, it says not emitting has value.

As I’ve said many times before, the lack of progress in deploying CCS up until this point is not a question of cost. It’s really been a question of finance.

The Future Act creates that financing.

I identified an additional provision which said not only can you consider a power plant a source or an industrial site a source, you can consider the air a source.

Even if we zeroed out all our emissions today, we still have a legacy of harm of two trillion tons of CO2 in the air, and we need to do something about that.

And this law says, yeah, we should. It says we can take carbon dioxide out of the air and turn it into stuff.

At the Petra Nova plant in Texas, my understanding is the carbon capture costs are something like $60 to $70 a ton, which is still going to outstrip the tax credit today. How are we going to close that gap?

There are many different ways to go about it. For example, the state of New Jersey today passed a 90 percent clean energy portfolio standard. Changing the policy from a renewable portfolio standard [which would exclude CCS technologies] to a clean energy standard [which would allow them] allowed higher ambition.

In that context, somebody who would build a CCS project and would get a contract to deliver that power, or deliver that emissions abatement, can actually again get staked, get financed, and get built. That can happen without any technology advancement.

The technology today is already cost competitive. CCS today, as a retrofit, is cheaper than a whole bunch of stuff. It’s cheaper than new-build nuclear, it’s cheaper than offshore wind. It’s cheaper than a whole bunch of things we like, and it’s cheaper than rooftop solar, almost everywhere. It’s cheaper than utility-scale concentrating solar pretty much everywhere, and it is cheaper than what solar and wind were 10 years ago.

What do you make of the critique that this is all just going to perpetuate the fossil-fuel industry?

The enemy is not fossil fuels; the enemy is emissions.

In a place like California that has terrific renewable resources and a good infrastructure for renewable energy, maybe you can get to zero [fossil fuels] someday.

If you’re in Saskatchewan, you really can’t do that. It is too cold for too much of the year, and they don’t have solar resources, and their wind resources are problematic because they’re so strong they tear up the turbines. Which is why they did the CCS project in Saskatchewan. For them it was the right solution.

Shifting gears to direct air capture, the basic math says that you’re moving 2,500 molecules to capture one of CO2. How good are we getting at this, and how cheaply can we do this at this point?

If you want to optimize the way that you would reduce carbon dioxide economy-wide, direct air capture is the last thing you would tackle. Turns out, though, that we don’t live in that society. We are not optimizing anything in any way.

So instead we realize we have this legacy of emissions in the atmosphere and we need tools to manage that. So there are companies like Climeworks, Carbon Engineering, and Global Thermostat. Those guys said we know we’re going to need this technology, so I’m going to work now. They’ve got decent financing, and the costs are coming down and improving (see “Can sucking CO2 out of the atmosphere really work?”).