emergency action to reduce atmospheric greenhouse gasses
[...]
live in denial
Too late for both. For an easy to understand explanation, see for example https://xkcd.com/1732/ or https://www.youtube.com/watch?v=N5UugtV06qw
For an easy to understand explanation
You mean an incorrect, painfully simplistic waste of my time (the video). Yes the $20million bet is a nice thought, give it a try, it will likely fail. As for the beginning of the video, planting 20 million trees (1 trillion is a more relevant goal) is not the only method of drawing down greenhouse gasses(!). I could list others, but surely you, and the creator of that watching-paint-dry video can use google for yourselves. Obviously there are also temporary geoengineering techniques that could buy us time.
It is not clear that it's physically too late. If human society focused a fair portion of our present industrial capacity on fixing the problem, almost unimaginable things could be achieved. The far bigger problem is human nature, stupidity and the corrupt ruling classes.
As for being too late to live in denial... it's never too late for that. So many of us will do that until they die - being immune to evidence or reason.
Edit: I now see they were suggesting 20million trees twice per day... sorry, was trying not to nod off.
Given that humanity is too useless to take sensible, emergency action to reduce atmospheric greenhouse gasses, now we all get to sit around and watch the resulting horrific dieback of planetary life.
Of course people are still free to live in denial and believe whatever alternate-reality nonsense their brainless peer groups have been fed by corporations propping up profits.