How do we get Earth back to something resembling the steady state we know can work long term?
1. Electrify almost everything that can reasonably be electrified.
Move quickly to EVs, and replace anything that can practically become electric with an electric version. Self driving & fleet utilization will push transportation cost per mile lower than ever before.
For the power grid, data centers, and other large 24/7 consumers: solar + wind + battery storage. Deep geothermal also looks interesting.
Build lots of desalination capacity.
Maybe even planes can eventually be electrified. Imagine shorter hops with battery swaps at sea (aircraft carrier sorts of things). Too crazy?
2. Deal with the things that are much harder to electrify.
Cargo ships.
Long haul aviation, if the electric plane idea really is impractical.
For those, we can turn energy + CO2 into liquid fuels, creating something closer to a closed carbon cycle.
3. Remove excess CO2.
CO2 persists in the climate system for 200+ years, so getting emissions to zero does not necessarily return atmospheric CO2 to previous levels.
We will need to remove enough to be net negative & over time bring it back down to the CO2 levels we know worked long term.
That takes energy. Fortunately, solar + wind + storage are cheap enough now & getting cheaper.
4. Find places for all that solar.
Deserts are obvious.
Floating solar could potentially contribute.
Agricultural land is interesting too. Agrivoltaics can sometimes provide useful shading while still allowing crops to grow.
5. Deal with the transition period.
Once we are making a serious transition toward decarbonization and carbon removal, it may make sense to investigate temporary solar geoengineering, such as injecting reflective aerosols into the stratosphere, to partially counteract warming while atmospheric greenhouse gas concentrations are being brought down.
The purpose would be to stop the feedback loops such as more forest fires, thawing permafrost, and loss of ice and other reflective surfaces.
Obviously geoengineering has major risks and should not substitute for reducing emissions. But as a temporary bridge, it seems like something that deserves serious research.
We can do all this.
None of it requires magic. We already have, or can plausibly engineer, most of the pieces.