Actually the models in the 1990s have predicted rather dire consequences for 2015.
Interesting. Examples?
At some point it is too late to avoid the disaster and better start preparing for it.
Probably true, though probably the sequence actually goes: disaster avoidable → disaster unavoidable but severity can be mitigated → disaster unavoidable and unmitigable, time to prepare → too late for anything, we’re screwed. And I’d have thought that second phase might be quite prolonged.
Anyone who predicts do X now or disaster will happen in 20 years and then X is not done loses a lot of cred when they still advocate X.
Only if X is only worth doing if done immediately. What reason is there to think that’s the situation here?
Imagine the following super-crude model of climate change. In year 0, we discover that from year 50 onwards the temperature is going to rise by 0.2 degrees (Celsius) per year. There is a drastic action we can take to stop this; if we do this in year Y, the warming will stop in year Y+50. In year 100, regardless, the whole thing will magically stabilize at whatever temperature is reached then.
In this model, if we do nothing then from year 100 onwards the temperature is going to be 10 degrees hotter than now, which it’s fair to say will screw a lot of things up very badly. In fact, just doing nothing for 20 years guarantees 4 degrees of temperature rise, which is probably enough to be pretty catastrophic. So the alarmists say: “We must take action within 20 years or it’ll be a disaster!”.
OK, so now it’s 20 years on and no one has done anything yet. We have 4 degrees of temperature rise ahead of us, whatever we do. But the right thing to say isn’t “OK, disaster is unavoidable, let’s just prepare to cope with it” because the magnitude of the disaster is still open. If we take action now in year 20, we only have 4 degrees of temperature rise to cope with. If we give up on stopping the warming and switch to disaster preparation, we have to prepare for 10 degrees of temperature rise, which is much worse.
(And without the cutoff in year 100, if we give up and switch to disaster preparation then the disaster we have to prepare for is the near-certain extinction of the human race within a few centuries.)
For the avoidance of doubt, I am not putting this forward as an accurate account of the actual climate change situation! But it seems to me to have a lot of features in common—possible disaster ahead, considerable lag between action and eventual consequences, taking action sooner means smaller effect. And in my toy model, it seems very clear that a sensible and sincere “alarmist” will both (1) say “disaster ahead if we don’t act really soon” and (2) continue saying that for a long time as no action continues to be taken. Which is exactly what you’re saying they shouldn’t be saying in the real world. What are the relevant differences that make your inference a good one in the real world and not in my toy example?
Interesting. Examples?
Probably true, though probably the sequence actually goes: disaster avoidable → disaster unavoidable but severity can be mitigated → disaster unavoidable and unmitigable, time to prepare → too late for anything, we’re screwed. And I’d have thought that second phase might be quite prolonged.
Only if X is only worth doing if done immediately. What reason is there to think that’s the situation here?
Imagine the following super-crude model of climate change. In year 0, we discover that from year 50 onwards the temperature is going to rise by 0.2 degrees (Celsius) per year. There is a drastic action we can take to stop this; if we do this in year Y, the warming will stop in year Y+50. In year 100, regardless, the whole thing will magically stabilize at whatever temperature is reached then.
In this model, if we do nothing then from year 100 onwards the temperature is going to be 10 degrees hotter than now, which it’s fair to say will screw a lot of things up very badly. In fact, just doing nothing for 20 years guarantees 4 degrees of temperature rise, which is probably enough to be pretty catastrophic. So the alarmists say: “We must take action within 20 years or it’ll be a disaster!”.
OK, so now it’s 20 years on and no one has done anything yet. We have 4 degrees of temperature rise ahead of us, whatever we do. But the right thing to say isn’t “OK, disaster is unavoidable, let’s just prepare to cope with it” because the magnitude of the disaster is still open. If we take action now in year 20, we only have 4 degrees of temperature rise to cope with. If we give up on stopping the warming and switch to disaster preparation, we have to prepare for 10 degrees of temperature rise, which is much worse.
(And without the cutoff in year 100, if we give up and switch to disaster preparation then the disaster we have to prepare for is the near-certain extinction of the human race within a few centuries.)
For the avoidance of doubt, I am not putting this forward as an accurate account of the actual climate change situation! But it seems to me to have a lot of features in common—possible disaster ahead, considerable lag between action and eventual consequences, taking action sooner means smaller effect. And in my toy model, it seems very clear that a sensible and sincere “alarmist” will both (1) say “disaster ahead if we don’t act really soon” and (2) continue saying that for a long time as no action continues to be taken. Which is exactly what you’re saying they shouldn’t be saying in the real world. What are the relevant differences that make your inference a good one in the real world and not in my toy example?