Rapid warming may destroy/displace >= 90% of life as we know it. It's happened before and we have records of it below the surface. Also >= 10°C is seen as mass-

Rapid warming may destroy/displace >= 90% of life as we know it. It's happened before and we have records of it below the surface. Also >= 10°C is seen as mass-destructive even if slowly introduced. We're not potentially heading there before a couple of hundred years, but the cascading nature of unknown effects doesn't make such scenario too unlikely and even a middle path will be largely destructive in the meanwhile.