Related: GoogleX co-founder Tom Chi gave a fantastic talk on carbon debt (with a rather depressing 238 views at the moment; I hope more people watch...):
Main takeaway is to view the problem as debt which has to be paid off. Simply stopping new purchases will not pay off the debt.
Above point summarized here, timestamp 22:15 - https://youtu.be/QyQvfaW54NU?t=1335
We currently have a one trillion ton carbon debt. As a though experiment, for a starting solution to iterate upon, this can be "paid off" with 20 billion trees / year, for 50 years. It would take 9000 drones, 450 staff, $80 mil/year. And a total land area half the size of Brazil. Using current technology. Compare this with alternative approaches being thrown around with price tags of 1 trillion+.
> Even if we emitted no more carbon from this point on, the planet would continue to warm on average and destabilize for about another 500-800 years.
Please go watch it. It's just 30 minutes of your time and it's very unlikely you already know everything he's about to mention.