I have repeatedly heard scientists say that planting 1 trillion trees will singlehandedly set climate change back 10 years. I've done the math on that myself and found that such a plan is about 5000 times more cost-effective than driving Tesla vehicles: https://news.ycombinator.com/item?id=19714034
Anytime anybody says anything about the social cost of carbon being greater than $0.50 per ton, I just tune them out.