[ggm]

Ah.. The "tackle the bigger fish first argument" - It's a false one: tackle all the independent paths at once because they are not linked. 2% is huge, its 1/50th of the burden. There are 250 economies worldwide, its larger than several nation states yet nation states are taking action.

You know where I got this? Gen. Groves. During the Manhattan project, asked if they should do one of two choices he said do both. This later paid back when it turned out thermal diffusion could pre enrich the feed for other techniques like the calutron and improve its efficiency.

[svara]

But there are some actions that can deliver huge gains immediately (e.g., replacing coal plants by almost anything else) for a low cost (both in terms of money and reduced standard of living / reduced growth). Reducing air travel is great, but there are few alternatives and not doing it at all anymore would drastically change modern society.

A carbon tax would make that discussion moot though: It can be adjusted dynamically to follow a defined CO2 reduction schedule, and carbon savings would come from low hanging fruit first, and ultimately affect everything.

[peterwwillis]

You have to weigh multiple costs, though. What's the cost of waiting to find out if the one huge gain is enough, versus the cost of doing them all right now?

It seems like a lot of the small changes with small impacts could actually cause a larger ripple effect which might end up causing the larger changes. Perhaps small changes, once accumulated, could be the key?