It wouldn't be pleasant, but it might buy us a few more years.
What I mean is, if we had a Second Great Depression with 25-percent unemployment, aggregate economic demand would plummet, as would the production of goods and services---and with it, we'd see a steep decline in the demand for fossil fuels. No purpose in drilling for oil if people aren't driving their cars, and there's point in fracking if people can't pay their utility bills. Like I said, not a cheery scenario, but that very well might be what it will take to save the planet, if it can still be saved at all.
---Baron V