Thread by @Peters_Glen

It is nice to see suggestions for the SSP/RCP framework to include more realistic reference scenarios, building on the work of @hausfath (nature.com/articles/d4158…) & @_neil_grant (nature.com/articles/s4155…) & others

A few thoughts:
1/
nature.com/articles/s4155…

2/ Does it make sense to include current policies or NDCs across all SSPs? Doesn't the existence of current policies or NDCs begin to preclude some SSPs?

One could use SSP2 (current socioeconomic trends) with scenarios performed with varying SPAs.

3/ This is really a challenge of the SSP/SPA/RCP framework. The three axes are essentially assumed to be independent, this makes theoretical sense but not really practice sense. I understand why that decision was made, but does it make the framework too unrealistic?

4/ The feasibility of SSP5-85 can be discussed (he, he), but the fact that it does not include feedbacks from climate impacts on the economy is ludicrous.

Perhaps the framework allows inclusion of impacts, but literature never does, so it is effectively excluded.

5/ Likewise, theoretically, it is possible to follow SSP5 (fossil fuel world) & get to RCP1.9, but it is pushing the realms of reality (if you ask me).

SSP1 (sustainability) without climate policy 🤔, SSP1 with high growth 🤔 (maybe, but it is not unique).

6/ I do like the SSP/RCP framework for many reasons, but we have to acknowledge it has a few rather strong weaknesses.

I am not going to pretend I have a better alternative. Maybe one alternative is to stop assuming the axes are independent.

7/ I did react to this part of the paper, where it acknowledges the need to include impacts, but the wording is so weak it feels like the authors think it is too hard, impractical, etc (maybe I read too much into the text).

[I would have preferred "let's figure how to solve it"]

8/8 Read the paper, it seems to be open access (for now), and I am keen to hear peoples thoughts...
nature.com/articles/s4155…