We shot up from 1 Billion to 7 billion in span of 150 years, and reversion to mean can happen, it is happening as lowering sperm count, and falling birth rates, climate change, global pandemics, war etc.

Read my comment as glass 1/7th full, at least there is some water left.

edit: As far as coal consumption from year 2000 goes, China has built massive coal consumption capacity and if China does not sign up to any of those Climate Change agreement, the rest is inconsequential since they are the workshop of the world now. You can tinker energy policy in US and Europe, but that means nothing if China is not on board.