My friend Brandon Liu introduced me to this interactive calculator, showing different policies and their effects on global climate change. Here is the FAQ for the simulator.

It's quite in-depth and allows tweaking many different factors and assumptions, and it also shows many different charts. Some general takeaways from playing with the calculator which were surprising for me and might be worth discussing:

1. Reducing deforestation does very little to help reduce global temperatures by 2100. I know that the default EA position on climate change as of a few years back was "support CoolEarth because Doing Good Better said it was cost-effective", and I'm not sure how it's changed since. But it seems worth pointing out that the overall benefit from reducing deforestation (and also planing more trees ala afforestation) seems likely to have a very low upper-bound on its benefit.

2. Carbon capture technologies, in the most optimistic case, does help, but reducing emissions via carbon taxing/pricing still plays a bigger role. I'd previously prioritized such research because it seems like one of the few ways we can go carbon-negative. However, it seems like this simulation assumes we can't scale up the tech fast enough to bring us back to 2010 temperatures, even with the most optimistic settings the simulation allows.

(I note being confused by this because of previous conversations with people who have mentioned that other types of geoengineering interventions like injecting sulfate aerosols into the atmosphere to help with global cooling could be easily deployed, and I don't think the model accounts for these sorts of strategies.)

3. As a result of 2., it seems that policies which price carbon higher seem like one of the highest things to prioritize, if you believe their models for how this changes our energy consumption profile (e.g. shifting from coal to renewables, etc. etc.)

4. Techno-optimism is likely overoptimistic. Even in the best-best-case scenario, where we institute the heaviest carbon pricing strategy, assume maximum research into more efficient fuels, assume heavy subsidies and taxes for clean/dirty energy, and assume maximum energy efficiency and electrification across all sectors, e.g. the techno-utopia scenario, we're still looking at 2C of warming by 2100.

5. Decreasing population growth by itself has a very small impact, which renders arguments like these quite weak. (Of course, there are also other moral concerns regarding efforts to reduce population growth, but I'm just pointing out that the proponents lose, even on their own grounds.)

6. Costs for adaptation are unaddressed. If we admit that it looks very, very difficult to get emissions down to where they need to be by 2100, then if we want to maintain the same standards of living, plausibly next thing to look into is ways of living which can deal with hotter surface temperatures, e.g. living underground. I'm unsure what the research for that looks like, or who's been working on this.

Overall, I think this is a fantastic tool that embodies a lot of the EA values, that's coming from a non-EA source. I think other EA issues could benefit from a similar sort of calculator. For other people who were confused about the scale of different interventions, I hope this proves to be a valuable aid.





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En-Roads is a systems dynamics model similar in purpose though much more complex and well-referenced than the World3 model of Limits to Growth fame.

Reference Guide:

is probably roughly accurate for the sector models of buildings and industry, growth, land and industry emissions, carbon removal, and non-electric transport. The electrification and energy supply sector model is not reliable, as the model simulates on a 0.125 year timescale which misses the market dynamics of electricity production. Furthermore, it calibrates the electric market projections against the IEA world energy outlook (WEO) which has continually underpredicted renewables and overpredicted coal capacity to an embarrassingly large degree: For example, solar capacity additions in 2016 were ~50 GW, WEO 2016 estimated solar additions would be roughly constant at 50 GW/year in 2018, reality was over 110 GW. WEO 2019 still assumes there will be substantial buildouts of coal plants in the U.S. and EU in the "current policies" scenario. The GIGO (garbage-in, garbage-out) applies here for the En-Roads electricity sector model - they calibrate against garbage energy supply projections from IEA, so the En-Roads analysis of electric sector policies will be grossly inaccurate.

This model error could significantly change your inference on points 3 and 4 once corrected. The rest of your points of inference are probably accurate.

Oh, awesome, thanks for sharing this useful bit of context!

Thanks for posting! I took an En-ROADS workshop with a trained facilitator in my local community and I thought it was extremely well done. The organization that built En-ROADS trains facilitators to then teach others about the tool (and about climate).

En-ROADS itself is an example of an intervention whose impact would be difficult to quantify. The goal is to educate as many people as possible about the fundamental dynamics of the climate problem, using well-designed interactive workshops/tools that are based on robust evidence. It seems like a good approach to me, but I don't know if they can ever prove a positive impact on the climate problem. I sometimes wonder if a similar approach would be helpful for spreading the "EA gospel" to a wider audience.

Great analysis. Many of these conclusions were not intuitive. 

For those looking to advance climate solutions, I'll plug Citizens' Climate Lobby which advocates for a price on carbon in Congress. I love political advocacy because it can be done with zero cost (ie writing to/lobbying your elected officials), and is a powerful tool for collective action. 

Thanks for the explanation on this, there's a lot to tackle when it comes to environmental issues and I sort of lost track of what has to be done, for what, in which direction, and what the realistic effects would be... I mean, when you've got issues as varied as CO² emissions, the plastic "island" in the Pacific ocean and deforestation, you feel like you'd need several brains to keep track of everything.

Still, I wonder whether the current state of the world's economy will bring more ecological practices. I mean, for example, I used to fly twice a year to Southern Europe to inspect stuff like this commercial real estate in Barcelona for my company, but these days, it's not necessarily, you can get an assistant on site to do a video visit of the items, or sign documents with electronic signatures.