Are Negative Emissions a "Myth"?

In a recent column for Project Syndicate, Lili Fuhr and Niclas Hallstrom rail against carbon capture and sequestration (CCS) and carbon dioxide removal (CDR) technologies, counting them among the group of "ineffective or impossible" solutions to climate change. The sad reality is that today, Fuhr and Hallstrom's conclusion is not that far from the truth for most most CDR solutions, which are not cost-competitive and/or technically-proven compared to other GHG abatement approaches. By far the best way to deal with climate change would be to follow Fuhr and Hallstrom's recommendation "to reduce emissions fast, while developing alternative energy sources that allow us to leave fossil fuels in the ground."

But while "this imperative is almost shockingly straightforward," the reality of the situation is that we are not reducing emissions nearly fast enough:

CDR Scenarios
CDR Scenarios

Above: Adapted from "Betting on Negative Emissions." 

So what happens in the event that we don't follow Fuhr and Hallstrom's prescription for preventing climate change? Or even worse, what happens if it turns out that we need to reduce CO2 levels in the atmosphere even further than we thought to avoid dangerous climate change? The only three options we would be left with are:

1) Failing to prevent climate change

2) Implementing highly untested and risky solar radiation management geoengineering techniques (such as injecting sulfates into the atmosphere)

3) Developing cost-effective and sustainable CDR systems to remove carbon from the atmosphere in addition to decarbonizing our economy.

None of these options sound great, but option 3 (deploying CDR technologies at scale) is the only one that a) prevents climate change by dealing with its root cause, and b) doesn't introduce completely novel risks to our society in the process.

So while CDR solutions might be ineffective today, CDR solutions could prove to be an absolutely critical option to preventing climate change in the future. Fuhr and Hallstrom are also right that some CDR approaches like biomass energy with CCS (bio-CCS) could "have enormous development implications, provoking large-scale land, most likely from relatively poor people." But Fuhr and Hallstrom are wrong that these negative consequences definitely "would" happen, especially if a large portfolio of CDR approaches (spanning not just bio-CCS but also biochar, direct air capture, reforestation/ecosystem restoration, land management, and enhanced mineral weathering) were pursued to provide negative emissions.

Instead of stridently arguing against CDR deployments, then, I would recommend that Fuhr and Hallstrom advocate for appropriate research on how to do CDR effectively and sustainably alongside broader decarbonization of the economy. Because the one thing I'm sure of is this: the reality of our current political situation makes it a distinct probability that we don't decarbonize quickly enough to prevent climate change. And given this reality, investing today in an appropriate amount of R&D to develop effective CDR solutions makes a lot of sense.