You are assuming that we have enough energy to harness all that energy from the sun. Extracting materials to harness all that energy costs energy, carbonized energy. Another issue is we don't really have 40 years anymore depending on how you look at it. So the issue still stands.
Crops do harness energy from the sun, but they can only do so at a certain pace which does not correspond to human pace, and in certain conditions, a stable given climate, which we are guaranteed to be leaving behind us now.
The issue is emissions not time. If you cut down emissions by say 75% then you have four times as long to hit the same amount.
Climate change isn’t some wall where X is absolutely fine and X + even 1% more is disaster. We are seeing negative effects today and they just get very slightly worse as emissions increase time the CO2 ppm increases by 1.
I mean, yes, that was implied, since we have not even starting decreasing the amount of carbon we let into the atmoshpere time = emissions. It's like I tell you I earn X$ dollars and month and then you tell me "Yes, but only if you go to work that month". I guess you are right but you're kinda missing the point. I really don't see emissions being reduced by 75% any time soon, so then, no, we don't have 40 years. Even if we stopped emitting carbon now, there would be bad consequences further down the road.
Exactly, this is not some wall and partly unknown territory, the thing is that this destabilization has inertia and we will suffer the consequences even after we have started actively removing carbon from the atmosphere if that ever happens. Another thing are self sustaining global warming mechanism that have been kicked off and that we don't know the effects of. So it won't get slighly worse, it is getting exponentially worse.
The US has dropped CO2 emissions by 15% since 2007. That’s a meaningful change.
Global numbers aren’t a rosy, but if you look at a developing country like China it produced 17.7% of their electric from renewables in 2008 and that jumped to 27.8% in 2019. While their economic growth more than offset that change, solar and wind adoption is currently much faster than economic growth both in China and around the world.
As to self sustaining global warming that’s not exponential. The current amount of CO2 in the atmosphere will result in a fixed amount of warming that hasn’t happened yet. It’s not an exponential increase just a lag between emissions and increases temperatures.
