What action would be taken by who?

There are literally hundreds of actions that could be (or in some cases have been) taken. I think the vast majority need to be taken by the government. Individuals mainly need to to support and demand these actions from the government, and punch climate change deniers in the face. E.g.

1. Stick to their plan to ban ICE car sales by 2030.

2. Unban on-shore wind power (Labour did this! Not that anyone noticed...)

3. Mandate solar panels and heat pumps for new houses.

4. Mandate bike lanes for new roads (blows my mind that this isn't a policy).

5. Take distribution into account when paying energy suppliers, so we aren't paying for a load of wind power in Scotland that we can't use (I believe this is being considered).

6. Upgrade the grid so we can get power from Scotland (I think this is in progress).

7. Make car charging infrastructure sane. No apps! Fines for broken chargers. More chargers along motorways. Street-side charging.

8. Stop freezing fuel duty.

9. Mandate OpenTherm (or similar) on boilers and thermostats.

10. Create an open, mandatory standard for remote adjustment of power consumption of things like air conditioners, freezers, car chargers and so on, that must be supported and can be used by power companies to optimise grid usage. Some large buildings do this but 99.99% of things that could do it don't.

11. Offer government backed loans for solar power. There are private companies that do it but they're seen as quite sketchy (e.g. if you sell your house...) so uptake is low.

12. Give office employees a right to work from home one day a week where it's possible (similar to how you have a right to change your hours).

13. Ban patio heaters.

14. Ban especially inefficient cars (e.g. less than 20 mpg).

15. Fix the railways... They are working on this tbf.