If we establish that the only number that is important is emissions, then the % of renewables is moot.
If 100% of new power generation was fossil fuel based, this could work if that amount was less than the amount of generation capacity lost from retiring fossil fuel infrastructure.
For example, if we pumped out 100MJ, and each year we added 2MJ from coal, but each year we retired 8MJ of existing coal generation, then we are on the right track (first year is a 6% reduction in FF-based generation).
Those are the only numbers that really matter.
I think touting our renewable numbers cloud the picture and encourage passivity; it creates the false notion that we are moving in a beneficial direction (when this couldn't be further from the truth). The theory is that by boosting green energy we will have the capability to *replace* fossil fuels. But a contradictory theory suggests we humans make no replacements, but maximize our consumption in this system (so renewables do nothing but increase system growth because they do not offset FF usage). To offset fossil fuel usage, we have to decide not to consume or sell fossil fuels; to just leave it in the ground. Can we collectively do that throughout the globe? Will our current system let us? Will this take a complete change in the structure of human civilization (something that isn't being examine while we green it up on an illusionary question to utopia)?
If humans can decide to "leave it in the ground" at some magical point in the future, why can't we now?