I’m pretty convinced that even with business as usual carbon emissions will drop like an anvil in most developed countries over the next decade.
Solar panels are getting so cheap, new plants will add many more panels than what their grid connection can handle. The industry refers to this as a high DC:AC ratio. You might have 300 MW of panels (DC) for 100 MW of inverters (AC). This means even when it is cloudy you are sending power to the grid at 100% of AC capacity. And you can produce at high output later into the evening. This makes solar firm power. In many ways this firm solar is more reliable than an analog fossil power plant. Most new projects also include batteries. They charge on DC so they can use some of the excess power during the day and then use the same inverter and grid connection to sell into the evening peaks. I’m not sure many people have fully internalized this change yet. Off grid folks have started doing it at a small scale, because it is cheaper to add more solar than buy more batteries to get through cloudy periods. You only need enough batteries to get you through the night.
Offshore wind is also going to be pretty incredible. The taller the turbine, the more reliable and predictable its power output. Onshore is limited by needing to truck the parts. Offshore is not limited and there are 10+ MW turbines coming out where onshore is usually no larger than 2.5 MW. It is technically challenging to keep going bigger, but some think it will go as high as 50 MW monster turbines. All three major US grids could have access to this resource. Instead of a 30% capacity factor for onshore, big offshore can be up in the 60% type numbers.
If you overbuild capacity, like using a high DC:AC ratio, there will be a lot of cheap DC power out there to use. Water electrolyzers to make hydrogen use DC. Hydrogen is a terrible vehicle fuel, but it is a good industrial feedstock. Eventually it may be converted to methane for use in homes and power plants.
If you do the learning curve math, any vehicle driving over 25,000 miles a year will be able to switch to electric and still be cheaper than running an existing, depreciated gasoline or diesel vehicle by 2030. There will still be lots of gasoline cars out there, but the average miles a gasoline car drives per year will drop a lot.
There is a lot of hoopla about ERCOT and what regulations and capacity should be. Unless most customers are exposed to real time incentives, any grid will always have periods of outages. Trying to get to 100% reliability only on the supply side is probably impossible and gets increasingly expensive.
Improvements in building heat, industrial, agriculture, and non-road transportation are harder for both political and technical reasons. Nuclear powered freighters, please! But cheap electricity and hydrogen would make them much easier to solve. You may have to live with ship and plane emissions or use direct air capture for those.
Part of me really believes we will be back to pre industrial CO2 concentrations somewhere between 2070 and 2100. There will be shortages of carbon as fossil fuel (soon to be a misnomer!) production rebounds and is stretched for use as material feedstocks. If that doesn’t happen, it will be a terrible slow growth tragedy.