Personally, I am thinking very hard about buying rural land in Canada, as global warming and mass migration may cause the price of land to go up substantially over time. I haven't run the numbers or pulled the trigger yet though.

Perhaps strategic land purchases, with the proviso that "the market can stay irrational longer than you can stay solvent."

There is a cap and trade scheme for certain CO2 emissions in the EU[1], and you could try to get exposure to the futures[2] for those emission rights. I see JE00B3CG6315 is a fund doing that.

Keep in mind though that the price can go to zero if the actual emissions go below the emissions cap, which happened in 2007. Presumably the EU will try to manage the cap to prevent that from happening again.

[1] https://en.wikipedia.org/wiki/European_Union_Emission_Tradin...

[2] https://www.theice.com/products/197/EUA-Futures

Energy generation, possibly energy storage.

Nearly all of our modern production, processing, and logistics to move it is constrained by the cost of energy. Any sort of atmospheric scrubbing is also energy restrained, our food production is energy restrained as fertilizer is still produce from fossil fuels. Refined material costs are largely dependent on the fuel costs of extracting and processing raw ore.

The only problem with investing in energy production is it being a slow grind, you won't likely see any large gains, but it is a secure bet so long as civilization exists.

I think the time frame is too long to make good money investing, the holding costs would kill you as the returns eventually come. I think about it more like where do you want to put down long term roots, given the disruption that will be caused by climate change in many places.