Thread by @Peters_Glen

THREAD (without figures)

Four principles for thinking about CO₂ removal:
1. Don't forget the long game
2. It's not all about CO₂
3. Split, don't lump
4. Don't bet it all on being right

sciencedirect.com/science/articl…

2. First: Don't forget the long game

Cutting GHG emissions must remain at the center of that strategy: CDR would be too slow, expensive, and technically uncertain to replace the need for rapid emissions reductions.

3. Different roles for CDR:
* Mop up to compensate for hard-to-abate (or expensive-to-abate) sectors
* Mop up after agricultural sectors (net-zero GHG emissions)
* Draw down "legacy carbon" remaining in the atmosphere from past emissions

4. Can start deploying CDR now (e.g., ecosystem restoration or afforestation), but if gigatonne scale CDR is needed later this century, then now is the time to get started on developing and adopting appropriate policies for CDR research, development, & rollout.

5. Second, it is not all about the carbon

Different approaches to CDR have different resource requirements & different social & environmental impacts.

Are we talking about an individual farmer adopting cover-crops or a multinational cooperation doing Direct Air Capture?

6. Is BECCS all bad?

Compare a small BECCS facility fueled by local municipal waste with a BECCS system in which huge swathes of commercially farmed land provide switchgrass to fuel large power plants that pipe carbon dioxide long distances for sequestration.

7. Evaluating CDR at the level of broad technologies or practices obscures these differences. A complete assessment of CDR requires assessing not only cost and sequestration potential but also environmental and social impacts.

8. Third, split don't lump

Not all CDR is created equal in terms of social, economic, & environmental impacts, & nuanced positions are needed to distinguish better technologies, practices, projects, and policies from worse ones.

E.g, not all BECCS is created equal...

9. Fourth, Don't bet it all on being right

Large-scale CDR might fail, but rapid short-term emission reductions might not emerge either.

Don't put all your cookies in one basket whether CDR or rapid reductions, both are needed.

10. We agree that precaution precludes us from betting it all on CDR’s panning out as the models project. We also worry about making the opposite mistake by counting only on rapid emissions abatement.

11. A very good commentary by @climateMorrow, @sehric, @hollyjeanbuck, @katedooley0, @Oliver_Geden, @GhoshArunabha, @ABNJAMNSHI, @noel_johnny, @OlufemiOTaiwo, @sktalati, @jwilceclab, & some others that are not on Twitter...

Read for free @OneEarth_CP: sciencedirect.com/science/articl…