[allovernow]

Even the worst predictions of runaway warming are going to take decades, if not centuries, to manifest, and at worst we're probably talking about mass migrations as arable regions shift. Earth turning into Venus or Mars is unlikely and even if that is the case such a transformation would realistically take so long that it's frankly hysteria to call it doomsday.

[Sevrene]

The worst possible outcome as far as humans are concerned is an economical disaster which would lead to people with out money, food, or water. People die with out those, so it's likely they would be willing to fight to death for them. So the worst outcome in the distant future is probably a collapse of society as we know it. Migrants already cause a lot of political instability. Lack of resources already cause wars and deaths. This will be exacerbated by climate change, and to some degree already is now. For example, a shortage of food causes unrest and that unrest grows to the point it can be used to justify a conflict.

We have to have a lot of inaction to get to that point from here, but it's possible.

[allovernow]

The point is that none of this is going to happen overnight and though millions may suffer or die, there will be time for mitigation. Civilization won't end - which is the criteria for the doomsday clock. The inclusion of climate change may be well intentioned but it is inappropriate.

[Sevrene]

I think you're right that people often over estimate the suddeness of climate change, when in actual fact it is a slow process over a long period of time, so change will come slowly not like a big disaster that people might have in their heads.

But the economy and society can change suddenly. People denying anything is wrong keeps it going. Everything is fine until it isn't, then change can come suddenly. USSR I think is a good example of this.

The economy will run until the constraints make it fail. This already happens now sometimes. We just have the means and the methods to fix it, or prevent it. Global warming will cause those constraints and our abilities to change and the economy is not just magically going to keep going, unless climate change is deterred.

Lack of food, lack of money, lack of stable government, etc. I think these are all conditions for civilisation ending. I don't think it will go from the stability we have now to no stability over a very long period. It will be like a pendulum and it will oscilate until one thing becomes too many and it will be the straw that breaks the camel's back.

I want to make it clear I'm saying this is only a possibility, and only if no change occurs. I don't think is the most likely outcome, merely that it's possible.