Venus is an extreme example of an Earth-like planet with a very different climate. There is nothing in physics or chemistry that says Earth’s temperature could not one day exceed 100 C. [...] [Regarding ice melting -- ] That will take time, but very little time on a cosmic scale, maybe a couple of thousand years.
I’ll be blunt, remarks like these undermine your credibility. But regardless, I just don’t have any experience or contributions to make on climate change, other than re-emphasizing my general impression that, as a person who cares a lot about existential risk and has talked to various other people who also care a lot about existential risk, there seems to be very strong scientific evidence suggesting that extinction is unlikely.
But as a scientist, I feel it’s valuable to speak the truth sometimes, to put my personal credibility on the line in service of the greater good. Venus is an Earth-sized planet which is 400C warmer than Earth, and only a tiny fraction of this is due to it being closer to the sun. The majority is about the % of the sun’s heat that it absorbs vs. reflects. It is an extreme case of global warming. I’m not saying that Earth can be like Venus anytime soon, I’m saying that we have the illusion that Earth has a natural, “stable” temperature, and while it might vary, eventually we’ll return to that temperature. But there is absolutely no scientific or empirical evidence for this.
Earth’s temperature is like a ball balanced in a shallow groove on the top of a steep hill. We’ve never experienced anything outside the narrow groove, so we imagine that it is impossible. But we’ve also never dramatically changed the atmosphere the way we’re doing now. There is, like I said, no fundamental reason why global-warming could not go totally out of control, way beyond 1.5C or 3C or even 20C.
I have struggled to explain this concept, even to very educated, open-minded people who fundamentally agree with my concerns about climate change. So I don’t expect many people to believe me. But intellectually, I want to be honest.
I think it is valuable to keep trying to explain this, even knowing the low probability of success, because right now, statements like “1.5C temperature increase” are just not having the impact of changing people’s habits. And if we do cross a tipping point, it will be too late to start realising this.
I’ll be blunt, remarks like these undermine your credibility. But regardless, I just don’t have any experience or contributions to make on climate change, other than re-emphasizing my general impression that, as a person who cares a lot about existential risk and has talked to various other people who also care a lot about existential risk, there seems to be very strong scientific evidence suggesting that extinction is unlikely.
I know. :(
But as a scientist, I feel it’s valuable to speak the truth sometimes, to put my personal credibility on the line in service of the greater good. Venus is an Earth-sized planet which is 400C warmer than Earth, and only a tiny fraction of this is due to it being closer to the sun. The majority is about the % of the sun’s heat that it absorbs vs. reflects. It is an extreme case of global warming. I’m not saying that Earth can be like Venus anytime soon, I’m saying that we have the illusion that Earth has a natural, “stable” temperature, and while it might vary, eventually we’ll return to that temperature. But there is absolutely no scientific or empirical evidence for this.
Earth’s temperature is like a ball balanced in a shallow groove on the top of a steep hill. We’ve never experienced anything outside the narrow groove, so we imagine that it is impossible. But we’ve also never dramatically changed the atmosphere the way we’re doing now. There is, like I said, no fundamental reason why global-warming could not go totally out of control, way beyond 1.5C or 3C or even 20C.
I have struggled to explain this concept, even to very educated, open-minded people who fundamentally agree with my concerns about climate change. So I don’t expect many people to believe me. But intellectually, I want to be honest.
I think it is valuable to keep trying to explain this, even knowing the low probability of success, because right now, statements like “1.5C temperature increase” are just not having the impact of changing people’s habits. And if we do cross a tipping point, it will be too late to start realising this.