… climate change is not an existential risk… Earth isn’t going to become Venus, or anything like that
Last I heard, the big question was what positive-feedback “tipping points” exist, and at what CO2-level they become triggered. This would give quite wide error bars on what average heating is caused by a given quantity of cumulative emissions. If we can burn all the fossil fuels, turn the rainforests to desert, and vaporise all the methane clathrates, and still not end up like Venus, that’s… reassuring, I guess
Doing all that would be very bad. Not Venus, but enough to greatly decrease Earth’s carrying capacity for humans and everything else, for a long time. We really should want that not to happen. But methane clathrate release turns out not to be as rapidly self-reinforcing as once feared, and at this point there’s no longer an economic or technological reason to think we’ll need to keep using fossil fuels and cutting down rainforests long enough to get to that point. We’re already seeing slowdowns in net deforestation, in part because in some countries there is net reforestation, though rainforests in particular are being lost faster in part because these exist mostly in less developed countries, but even then it’s (2020 aside) slowing down.
Last I heard, the big question was what positive-feedback “tipping points” exist, and at what CO2-level they become triggered. This would give quite wide error bars on what average heating is caused by a given quantity of cumulative emissions. If we can burn all the fossil fuels, turn the rainforests to desert, and vaporise all the methane clathrates, and still not end up like Venus, that’s… reassuring, I guess
Doing all that would be very bad. Not Venus, but enough to greatly decrease Earth’s carrying capacity for humans and everything else, for a long time. We really should want that not to happen. But methane clathrate release turns out not to be as rapidly self-reinforcing as once feared, and at this point there’s no longer an economic or technological reason to think we’ll need to keep using fossil fuels and cutting down rainforests long enough to get to that point. We’re already seeing slowdowns in net deforestation, in part because in some countries there is net reforestation, though rainforests in particular are being lost faster in part because these exist mostly in less developed countries, but even then it’s (2020 aside) slowing down.