Dr. Genevieve Guenther (@DoctorVive): I'm increasingly convinced that so many people are getting excited about CDR because they're trying to stave off their own climate panic and grief.

And, look, I get it.

But keep in mind that whatever relief CDR offers us is delaying the moment of reckoning for our leaders too.

Amy Westervelt (@amywestervelt): @DoctorVive Also CDR will deliver the most benefits if combined with mitigation rather than replacing it altogether

Dr. Genevieve Guenther (@DoctorVive): @amywestervelt In my view it will be a miracle if we can scale tech CDR enough to remove 1 or 2 gt CO2 / yr (and I hope we do or else it'll be hard to have an industrial economy!), but the idea that CDR can remove 100s of gigatons and cool down the planet is a dangerous fantasy...


Amy Westervelt (@amywestervelt): @DoctorVive What’s also crazy to me: people forget afforestation and reforestation are also CDR strategies…that exist today

Dr. Genevieve Guenther (@DoctorVive): @amywestervelt that fossil fuel interests are using to justify continued fossil fuel production (in BS net zero plans) and that is having the psychological /political effect I tweeted about, above. 2/2

Dr. Genevieve Guenther (@DoctorVive): @amywestervelt I guess the CDR folks say that forests don't offer permanent removal?

Dr. Genevieve Guenther (@DoctorVive): @amywestervelt And PS I know it's a dangerous fantasy because the people who are disseminating it are hiding or ignoring the scientific research on CDR's limits.

Amy Westervelt (@amywestervelt): @DoctorVive Privately they say “fuck forests!” I kid, I kid. Totally agree that the magical thinking around some sort of massive scale carbon vacuum seems problematic at best

Zeke Hausfather (@hausfath): @DoctorVive @amywestervelt At least in WG3 models about half the CDR comes from biosphere storage (like forests). However, in model world they can be assumed to be permanent, but thats proving to be a bit of a challenge in a warming world: https://www.nationalgeographic.com/environment/article/forests-as-carbon-offsets-climate-change-has-other-plans

Zeke Hausfather (@hausfath): @DoctorVive @amywestervelt Plus the daily drumbeat of pieces like this. It doesn't mean forest CDR should be abandoned, but we should be really careful about treating it as counterbalancing a ton of emitted CO2: https://www.bloomberg.com/news/articles/2022-03-17/timber-ceo-wants-to-reform-flawed-carbon-offset-market

Dr. Genevieve Guenther (@DoctorVive): @hausfath @amywestervelt WG 3 models also employ a ton of BECCS, which nearly everyone agrees is largely infeasible. I don't think the models really tell us all that much.

Zeke Hausfather (@hausfath): @DoctorVive @amywestervelt True, but various other studies suggest an economic potential of around 100 GtC (366 GtCO2) for reforestation, which is in-line with roughly half the ~600 GtCO2 cumulative CDR deployment in 1.5C scenarios.

Zeke Hausfather (@hausfath): @DoctorVive @amywestervelt My concerns are more on the permanence side than the potential one. Making sure that someone is left holding the proverbial bag and is responsible for compensatory CDR if the forest burns down, is eaten by bark beetles, etc.

Zeke Hausfather (@hausfath): @DoctorVive @amywestervelt And avoiding stuff like this: https://twitter.com/hausfath/status/1518738030164471809

Dr. Genevieve Guenther (@DoctorVive): @hausfath @amywestervelt No, I get it! The permanence problem is real.