No, those numbers are from the IPCC which represents the mainstream consensus. Take it up with them if you think you are right and they are wrong. Using the 20 years number is reasonable considering how far along we are in climate change. As the IPCC report states: "There is no scientific argument for selecting 100 years compared with other choices (Fuglestvedt et al., 2003; Shine, 2009). The choice of time horizon is a value judgement since it depends on the relative weight assigned to effects at different times."
>...Under 10% total gen from peaking power is viable with over production of wind and solar and zero grid storage.
Yea I hear advocates make such claims all the time. Unfortunately I never hear the same thing from people who actually run a major utility. We might get there someday, but for now I have to agree with Gates: "...What they mean is that at noon in Arizona, the cost of that kilowatt-hour is the same as a hydrocarbon kilowatt-hour. But it doesn’t come at night, it doesn’t come after the sun hasn’t shone, so the fact that in that one moment you reach parity, so what? The reading public, when they see things like that, they underestimate how hard this thing is. So false solutions like divestment or “Oh, it’s easy to do” hurt our ability to fix the problems. Distinguishing a real solution from a false solution is actually very complicated."
Further, because of this decay increases in release rate don't stack at 86x year over year. You get a magnified increase in the first year and a smaller net increase every year after that until your down to the carbon content of methane.
Under 10% total gen from peaking power is viable with over production of wind and solar and zero grid storage. It's not going to be 10% 24/7 but 0 most of the day, regular generation at part of the day, and rare spikes up to 50%. You can drop that under 5% with moderate grid storage of around 1h average demand, but you start needing vastly more storage the lower you want to take that number.