One can take a very broad brush view of the US and energy and then consider the other Big Players and their situations. Take a few common facts:
1. About a quarter of US CO2 generation is from transportation (burning oil in essence). You can put a pretty good dent in that with fuel economy increases and more EVs over time.
2. The other 75% or so is in electricity generation, which is about a third natural gas and a third coal and 20% nuclear. So, that is 2/3rds that is fossil fuel today, and cutting that while also allowing for more demand as the country grows is "challenging".
3. Wind and solar account for about 6% today to the grid, hydro is about 8% (and not growing).
You can DOUBLE wind and solar (which is less than 1%) over the next decade and barely keep up with growing demand, leaving that 2/3rds figure unchanged. You have to TRIPLE it to make a small dent in coal and NG, and of course if cars go electric you have more demand from there as well. Small dent in rate of increase, not turning it negative.
And tripling wind and solar are simply not going to happen in a decade. That is beyond the wildest growth estimates out there.
So, now consider China, left to the side of Paris until 2030 when they claim they will cap CO2 emissions magically. Up until then they can pretty much do whatever and India is the same. Those two countries account for about half of the future CO2 generation globally over time, so whatever the US and Europe manage to do is diluted by China and India (and Brazil et al.) are not doing soon enough.
So, the realistic prospects of curbing CO2 emissions and getting them on a downward trajectory is many decades off and the damage to the climate done in the meantime is not reversible unless we're talking centuries at zero.
You can look in VAIN on the Internet for any quasi-realistic plan to cut CO2 emissions globally, I've looked. There isn't one, but you do find the same gloom and doom I list here by the MIT folks and others.
Unless ITER generates (ha) a major breakthrough in the next decade, which I don't expect either, we're basically screwed.