[andy_ppp]

I think we could do the following; local seasonal food farmed as naturally as possible. It’s likely to still use some carbon, but doing this would massively reduce what’s used today.

Tax meat production heavily.

Tax air travel heavily and these taxes should increase exponentially per journey per person.

Stop shipping goods half way around the world… make the things you need locally.

Improve the grid and invest in plans for heating using electricity.

Build hundreds of small nuclear plants.

I think that’s net zero roughly but it’s not possible politically even though it’s a feasible solution to the problem.

[zarzavat]

This is the conventional wisdom, but as you mention it's not politically possible. It would be hard for one country to enact all of these changes, let alone all the world's countries.

There is an alternative path and that is radical renewable energy production. Many of the things you mention are not intrinsically harmful, they are only harmful because of the dependency on fossil fuels. For example, shipping things around the world is not intrinsically harmful, it is only harmful because it today requires fossil fuels.

From this perspective the actual problem is a shortage of renewable energy. If we build vastly more renewable energy capacity then we can make fossil fuels economically unviable. Since that is a problem of money rather than politics it is much more viable as a solution.

[andy_ppp]

The alternative to what I’ve said is probably a pretty horrendous dystopia because we still have nowhere to store renewables let alone a process that can make the type of diesel used in container ships…

[ZeroGravitas]

I strongly doubt that local food production would be less carbon intense. The reason for producing food in far off, but often sunny places is generally about accessing the free solar energy they have as well as higher efficiency because they can supply the whole globe year round, rather than one nation on a weather dependant cycle.

Shipping isn't particularly polluting by it's nature. Currently we allow people to burn some really dirty fuels in ships on the basis that it won't directly affect too many local voters and the fossil fuel industry needs to do something with the stuff they can't burn near people, but it would be relatively easy to regulate and is generally tightening up over time.

Moving to clean ammonia or hydrogen engines is also very doable.

Carbon taxes are often a talking point for politicians that don't actually want to do anything but many of your ideas could be better implemented as carbon fees and/or tariffs so that it will optimize for greenhouse gasses directly, not for what people think is the carbon cost of something.