Sometimes we're very fond of claiming we are climate 'realists' and are sceptical because we look at the 'observations' rather than projections, and we are not alarmed by what we see. I think there is some truth in that, but I wonder how much we have become entrenched in a position, and the fatigue of the war makes us less flexible about the possibility we may be wrong. I think it's sometimes useful to confirm we are still acting rationally rather than tribally.

Let's leave aside the question of the amount of climate change / warming we can observe at the moment. This is more of a thought experiment to see what types of evidence would convince you on various levels that climate change is a real problem that has to be tackled. And then in what way would you wish to see it tackled given that you are now convinced.

Here's my go:

I suppose part of the answer of what evidence I need to become alarmed is an inversion of the question, what about the evidence presented so far fails to convince me. The temperature since mid-century is notable, but still within the realms of the natural variation we can see in suitably resolved records. Both quantity and rate of change are unusual, but not worryingly so. So....

(1) I would require an upward temperature trend which was obviously (subjectively) non-natural and rapid.

So the temperature goes up, I don't think people are really that worried about the temperature (judging by the doom-porn that the climate industry spews out) - what people worry about are the secondary effects, such as so-called climate extremes. Again, what I find un-alarming about the trends on hurricanes, storms, rainfall, floods, desertification and drought measured even by the IPCC (who are REALLY trying) is they cannot link it to CO2. So this would, when inverted, be my evidence. So...

(2) I would require evidence that climate extremes attributable to temperature are on the rise

Another part of my un-alarm is my belief in the ingenuity of we humans. Unlike the fear-mongers, I don't expect us just to sit here and let all low-lying cities become flooded, or dry up, or whatever doom scenario is predicted. Within reasonable amounts, we will cope, by damming and levees and more stringent planning rules, and construction specification, and alleviating works. These maybe expensive, but I'm convinced they are not prohibitively so. So...

(3) I would require costing to show that adaptation work is too expensive to afford and would bankrupt us

The last one is more of a touchy-feely one. I get that people want to save the world, that is the modern narrative that replaced 'saving souls' in the more secular age. But there is so much hypocrisy. People jetting off to climate conferences to tell us not to fly is pure pantomime. Why do these people never refuse unnecessary travel? Why do eco-charities continue to print paper marketing material? Why do 'believers' never life their lives as an example, except in desultory ways like putting their plastic bottles in a different coloured bin. If governments really wanted us to cut fossil usage, they would tax companies who disallow home-based teleworking, the would adjust VAT for non-resource v resource based products (e.g. a video game delivered to the home over broadband should not be taxed the same way as a lithium battery produced expensively and shipped across the world). So, my final one would be...

(4) I require that people, organisations and governments who say they are convinced by the case to behave absolutely in accordance with the rules they wish to impose on everybody else.

So, imagine a world where all my 4 are satisfied, say for instance 10 years from now. The temperature record has gone up to a place and at a rate that is subjectively at a place I cannot ignore as natural. It can be shown that storms and floods are increasing statistically at a rate which is also not able to be ignored. It has been shown that the economic impacts are massive and will seriously impact the world economy to the point of unaffordability, and in response, the government has made statutory changes to support the reduction of fossil use, and people generally are committed (in a sort of London blitz spirit) to curtailing their activity and purchases to support this.

Imagine I am now totally convinced something is wrong and we need to fix it. What would I do?

Another post, I think. In this scary world of 2026 when I am utterly convinced climate change is happening, what on earth could I personally do, and what collective decisions would I push and support. Needs more thought.

What would convince me there really was a wolf? After all the cries of "Wolf! Wolf! WOLF!! " ?

I think nothing less than the sight a big hairy wolf actually eating a shepherd boy would convince me.

One scenario is that people spend 40 years on futile gestures ..and then fusion comes along and properly reduces CO2.

Please let it not be 40 years.

Martin,

So what would be your definition of the "wolf eating the boy" - actual devastation of a few coastal cities in a small timespan?

TBYJ, it's not my job to do the alarmists work for them. (Bung me a $1million and you might test my moral fibre).

There are many other things for me to be worried about. And most of them will happen to me before I am about 140 years old, which, for some strange reason, seems to be the focus of the models touted by the global-warming alarmists.

This thread was less about them, than it is about us.

Our strength is that (some of us) had our minds changed once by evidence.

Just wanted to check that our minds were still available to be changed again, not that I expect it to happen.

Please let it not be 40 years.
Dec 14, 2015 at 1:11 PM TheBigYinJames

Fusion has always been fifty years in the future. Nothing on the horizon to change that.

If and when that *does* change, it will be something completely unforeseen and unexpected that enables it.

Although from the moment I first heard about it, it seemed obvious that cold fusion was complete bollocks, I thought it was a wonderful thing in that it would have meant at least one or two sleepless nights for those in charge of whatever was the main fusion project at the time.

[I'll tell you about the wolf later]

I very much doubt anyone will give you a well considered reply. Replies will be extreme to avoid any chance of being held to them. From your requirements:

1. Can you quantify your required trend? You are talking of only 10 years but trends are normally calculated over decades. How would you calculate this "trend" and how would you tell whether a fast "trend" was real or just a temporary blip.

2. As I was discussing with Martin on another thread, climate extremes are not directly attributable to temperature just like individual cancers are not directly attributable. And again, you are talking of just 10 years. Extreme events are rare enough that the pre-warming probability distribution is probably not very well known. Warming will shift that distribution towards the extreme but over just 10 years how would you know it wasn't just chance (as people like the Bishop will doubtless say in every case)? How would you do the attribution? Were the recent UK storms attributable?

3. What if the adaptation work was too expensive for someone else in some other country to afford and would bankrupt them? Say in lots of poor countries. I'm guessing that wouldn't qualify, or?

4. That is the way of a "tragedy of the commons". You won't change human nature.

I just think that to be taken seriously, anyone on the sceptic side has to have a set of criteria which would make them change their mind. To always doubt no matter what your eyes tell you is not to be a sceptic, but a denier. The fact that some cannot even countenance the idea that it might be real, even as a thought experiment, is quite instructive to me. I actually quite enjoy being proved wrong, I love the topsy-turvy feeling that anything might be possible.

Can you quantify your required trend?

It's subjective (as I alluded) but I'm happy to work out a figure that would satisfy me. If you take the generally accepted HADCRUT3 trend (link) it gives a rise of about 0.7 degree in the last 50 years. From the start of that range up until the start of the pause, this was around the 1.7 degree per century mark. it's now dropped to 1.4 degree per century because of the pause. I would start to get concerned if it's still 1.4 degrees per century or above by end of 2020. Then I will consider warming to be concerning. I'm sure you can see this is very reasonable and testable prediction. If the HADCUT3 trend from 1965 to 2020 is at or above 1.4 degrees per century then I will consider myself alarmed. I'll expect you to hold me to it. If you'd prefer me to use another recognised temperature record, I will recalculate.

As I was discussing with Martin on another thread, climate extremes are not directly attributable to temperature just like individual cancers are not directly attributable.

I know you were discussing it, but it's not relevant here. I'm not asking for individual events to be attributed - only the frequency/number to go up alarmingly. The equivalent would be the number of smokers who go on to get cancer has to go up before you can discern a causal link, even if you cannot directly link it in the individual cases. If there is an effect, then the numbers and frequencies will go up. If you can point me to a decent source of hurricane strength/numbers then I will calculate a similar prediction that would make me alarmed.

What if the adaptation work was too expensive for someone else in some other country to afford and would bankrupt them? Say in lots of poor countries. I'm guessing that wouldn't qualify, or?

I specifically said world economy. This means that if we got to the stage that we were having to plan and execute massive adaptation work around the world, then we would already have passed the point where we were convinced climate change was going to have a large effect. I expect I would have been convinced by then. In that case, I would be satisfied that these works need to be paid for collectively.

That is the way of a "tragedy of the commons". You won't change human nature.

I think this is also needlessly pessimistic. Surely you've heard of the Blitz spirit? Dig For Victory? When people have an existential goal, they are capable of amazing change. But they have to be convinced it is an existential goal first. Dire warnings with no discernible real-world effects is not going to do it. People live on the slopes of smoking volcanoes, not because they are stupid, but because they gamble on the odds being on their side. And they are mostly right.

But it does lend itself to a follow on question of: if I was utterly convinced it was going to get bad, but the evidence was not enough to convince "lay" people, what would I do. I suppose this is what true believers at the moment are faced with at the moment. Trying to convince the unconvinced, and unconcerned.

Geronimo: so what do you think about my personal assertion that unless you have a scenario in mind which would convince you that you were wrong, then you cannot class yourself as a rational sceptic?

I realise that current evidence is flaky and the tellers of the tale very shady. That wasn't the point of this, there are other threads for that :)

"Alarm" is something we should leave to the alarmists. The climate extremists are quite gifted in acting alarmed and pretty good in scaring people. They do not need reality to accomplish this. Only their ability to communicate the fear they have for the monsters in their minds.
Rational people could become concerned about climate if there were trends in climate events that were trending in dangerous directions outside the bounds of historical variability.
Since not one worldwide trend is doing this, we can continue to point this out and allow the alarmists to continue their pathetic anthropomorphic projections.

I just think that to be taken seriously, anyone on the sceptic side has to have a set of criteria which would make them change their mind.
Dec 14, 2015 at 2:59 PM | Unregistered CommenterTheBigYinJames

I'll take issue with that. There is an infinite supply of alarming hypotheses. A skeptic shouldn't have to have an a priori answer to all of them. You know, Occam's Razor and all that stuff.

RR, no sale.
He could, instead, have asked for situations where skeptics have changed their minds.

If you start trying to reverse the null hypothesis, then you are headed up into Entropic Man country.

A fair question to ask is, "What would it take for the believers to change their minds"?
In rational beliefs, when a set of predictions about a claim are demonstrated to be false, one changes their mind regarding the claim.
The list of failed climate alarm claims is long and growing.
Yet the gathered leaders of much of the world, supported by the self-proclaimed best and brightest, have made a global agreement that is in response to those provably false claims.
What would it take for those backing the claims of climate doom to reconsider their apocalyptic beliefs?

If you insisted that I play the game, I would say that I would truly be alarmed if Myles-11°C-Allen's BS came true by 2100.

Raff, per his earlier comment, might then say it wasn't a serious response on my part.
I would reply that Myles Allen couldn't be taken seriously either, and did he have a serious proposition for me to get alarmed about.

I hope TBYJ can see my earlier objections to the question more clearly now.

Sorry Michael, I still don't see your objection.

There is no null hypothesis reversing going on here. I am asking what evidence you personally would require in order for you to reject the null hypothesis and embrace the AGW hypothesis. I find it instructive and amusing that some people cannot or will not countenance even talking about it, as if they might get corrupted by the naughty talk, or it might give the other side assistance, or whatever reason.

It's not playing their game' - I'm not commenting on the likelihood of it happening, just asking what would it be. There is no right or wrong answer. Some people would need more evidence than others. Perhaps my threshold is lower than yours, perhaps some people will never believe it. I'm just interested in what it would take for a variety of us here.

I still maintain that to be taken seriously as a doubter, you must have a scenario where the doubt is expelled. If the evidence is wanting at the moment, then there must be a threshold where the evidence becomes sufficient. If you can never be convinced then your stance is more ideological, not evidence-based. Dare I say denier-ish.

Big Yin said:

I just think that to be taken seriously, anyone on the skeptic side has to have a set of criteria which would make them change their mind.

Your worrying trend of 1.4C/century is doubtless well meant. I don't understand why HADCRUT3 should be a reference and not 4 (I didn't realize 3 was still maintained) and I don't understand where the two trend values come from. How did you detect a change point? In this Real Climate article no such point is shown. The implication is that the trend is and has been 1.7/century and that you should perhaps set your worry point target to 1.7 in 2020 (a sterner test).

HOWEVER, I fully expect the pause meme to maintain through this year's probable record temperatures (2015 was an el Nino year, you know, it was a blip, it doesn't count, the records were fudged, the satellites are the "gold standard" etc) on the lips of those whose positions are immune to changing circumstances.

I take your point about attribution. But I don't know how you would reliably detect an increase. If event severity follows a normal distribution and warming pushes up the mean of the distribution, then the event probability at any given extreme on the RH tail increases. But extremes are rare and it takes many events to plot a distribution. Randomness could easily result in a sharp increase or decrease in events without there having been any change. Again for this reason I fully expect "skeptics" to argue that whatever is thought to be an increase is, in fact, not.

Adaption in poor countries will just equate to suffering by those without the resources to escape. The West probably won't even see it and the usual suspects will put it down to bad government or building in the wrong places or lack of dredging or whatever. I very much doubt that rich country taxpayers are going to pay for such adaptation - all aid is bad, don't you know?

Am I pessimistic. I am really. It is in nobody's individual interest to act unilaterally (at least one climate blog I read often resembles a travelogue). The Blitz Spirit was doubtless marvelous, but what other option did people have? Dig for Victory clearly targeted individual interest. There's no equivalent apart from a carbon tax and dividend giving people individual incentive to maximize their return. Without such a policy, I don't see anything changing in public mind. Climate change resembles pension saving in that it is just not so important in everyday life - until it is too late. Only if something hits home will people and maybe governments take notice (maybe being flooded out of a house will do it for some).