Wednesday, December 16, 2009

Climate Change: The Need for Proof Argument

You are the first mate on an ocean liner, when the Captain gives the following order. "You are to proceed at full speed without any deviation in course and speed unless and until you have absolute proof that there is an iceberg straight ahead. Then and only then are you permitted to take preventative action."

Or, you are an adult supervisor on a bus trip with a bunch of school children. The bus is approaching a train crossing. Yet, the driver says, "I am not slowing down unless and until I have absolute proof that the bus will not be across the tracks before the train gets here."

We know these people to be guilty of the moral crime of reckless endangerment.

If these types of people wish to take actions that risk their own lives, we may leave that up to them. They pay the costs for their own mistakes. However, when they put the lives of others at risk, then they are guilty of a moral crime.

We have good reason to condemn people like this and to condemn them in very harsh terms. They are responsible for the deaths and suffering of a great many people every year.

Now, we have a whole slew of these types of people engaging in reckless endangerment of whole cities and whole populations. They have already maimed and killed a great many people and destroyed a great deal of property, and they seem to have no qualms about continuing along the same course of action. In all cases, they behave as people who are almost if not entirely indifferent to the death and suffering of others - because they are not motivated to take any action that would avoid potential death and suffering.

The morally responsible person would not demand proof that there is an iceberg straight ahead before slowing down and taking precautions. The mere possibility of an iceberg is good enough. His responsibilities to his passengers demands that he take precautions to reduce the possibility of catastrophe - not that he act as if there is no risk until catastrophe is certain.

The responsible bus driver will not risk racing the train at the crossing. She will take precautions to protect the well-being of the children trusted to her, which means slowing down and avoiding the possibility of harm coming to them.

These same principles of moral responsibility demands that, in the face of risk of massive destruction due to climate change, that people slow down and reduce the risk. It does not require absolute proof.

Principles of rationality give us a simple formula for determining how much caution to use in the face of risk. The basic form states that the amount that it is rational to spend avoiding risk is equal to the cost times the probability.

It is worth spending up to $250 billion to avoid a 1% chance of suffering $25 trillion in harm.

It is worth spending up to $2.5 trillion in avoiding a 10% chance of suffering $25 trillion in harm.

It is worth spending $12.5 trillion to avoid a 50% chance of suffering $25 trillion in harm.

It is worth $22.5 trillion to avoid a 90% chance of suffering $25 trillion in harm.

This is what rationality and moral responsibility commands. Those who do not follow this formula are guilty of reckless endangerment. When we think of them, we should have the same reaction that we have thinking of the cruise boat captain demanding absolute proof of an iceberg or the bus driver demanding absolute proof that she will not make it across the tracks in time to avoid the train. Except, we should think of those who use the "Need for Proof" argument as willing to risk the destruction of whole cities and whole populations.

As it turns out, the "Do nothing" subset of global warming deniers are recommending exactly the same course of action as an arrogant and presumptuous person who claims, "There is a 0% chance that I am wrong when I say nothing bad will happen, and a 100% chance that anybody who says otherwise, regardless of the evidence they provide, must be mistaken."

It is worth spending $0 to avoid a 0% chance of suffering $25 billion in harm.

While these people like to crow on about the fallibility of science, they neglect to mention their own fallibility - the possibility that they are wrong and that these costs are real. They argue that the fallibility of science means that it is not permissible to take any (or only the most minimal) steps in avoiding harm. They argue that we should behave as if they, the global-warming deniers, have a greater than 99% chance in being right in claiming that no harm will come from greenhouse emissions. That all of the evidence collected to date provides a less than 1% chance that they are wrong, and that we may behave accordingly.

If you see this "Need for Proof" argument in the claims made by somebody writing on global warming policy, you know you are dealing with somebody with a moral character many times worse than that of the ship captain or the bus driver that I mentioned above. You are dealing with somebody who will risk the lives of not only a few hundred passengers or a couple dozen school children, but is willing to put whole cities at risk. You know that you are talking to somebody who lacks the moral character to act in a morally responsible manner.


Rex said...

I am so sorry to have to respectfully disagree again.

Your logic is unassailable. For me that is not the issue.

You have devoted much of this blog in the evaluation of faith (in religion) as a flawed world view because it blinds the faithful to things that they would clearly see if they would be objective.

I find faith in a man caused environmental cataclysm to be wanting.

I have said before, that I think that we should not be reckless with our environment and resources, but to turn the Titanic around and go home because there MIGHT be an iceberg out there doesn't seem like the right response.

Let's step back from the environmental issue just for a moment and let me ask you to substitute the phrase "suffer God's wrath" in place of "face an environmental catastrophe".

If we were bombarded with gray beards telling us that we need to cease burning fossil fuels or we would suffer God's wrath, I think your response would be different.

I know my argument is a straw man, and has other flaws, but I am sure that you get the underlying concept that I am trying to illustrate.

Substitute a religious consequence in place of global warming and make the same argument. Would you? Could you? I don't think so.

Eneasz said...

I don't think the argument is to turn the Titanic around, but to slow it down and proceed cautiously, with the amount of caution proportionate to the likelihood of hitting an iceberg.

And the grey-beards can be dismissed because their claims have no basis in reality, much like those who warn of the wrath of a dragon/smurfs/klingons. If you are trying to get people to spend resources on preventing a disaster, you should be able to show that the potential for disaster actually exists. Those who warn of the wrath of virulent microbes or a changing climate have provided a great deal of evidence to meet this obligation.

Alonzo Fyfe said...


You are correct to point out that this particular piece of flawed reasoning has a flip side - the person who argues for TOO MUCH caution given what is known about the threat.

My intention is to deal with a particularly attrocious example of that, which has turned up in some current commentary, tomorrow.

Dan said...

The Climate Change is absolutely normal, and your logic seems really scary to a point of a religious argument.
You should know that Volcans produce more CO2 than all the Companies in the world, and the major producer of Co2 in the world is the ocean.
Thats why we should take care of our oceans better; because with out the ocean we might not be able to survive even protecting the Co2 emissions.

Alonzo Fyfe said...

Your statements about volcanoes is false. Humans produce more CO2 in 1year than all of the volcanoes in the world produce in 40 years.

It is estimated that volcanoes release about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere each year. This is about a factor of 100 smaller than the sources from human activity.

Wikipedia: Carbon Dioxide

Furthermore, volcanoes produce a CO2 at a rate the rate that can be absorbed back out of the atmosphere. This is shown by the fact that 10,000 years of volcanoes produced no change in atmospheric CO2 concentrations. Whereas atmospheric CO2 concentrations have gone up every year for the past 50 years.

Has volcanic activity also gone up?

Human activity has produced the only new source of CO2 over the past 50 years, and the CO2 levels have gone up by less than the amount that humans have added to the atmosphere. These facts combine to make it certain that humans are responsible for increased CO2.

The posting on The Three Percent Argument explains that.

Alonzo Fyfe said...

Also, Dan, the oceans release more CO2 into the atmosphere than humans, but they also absorb more than they release.

The systems were in equilibrium.

This is why, even though the oceans have existed and have been releasing CO2 into the atmosphere for the last 10,000 years (at least), CO2 levels have remained constant (between 260 and 280 ppm).

You cannot explain the fact that atmospheric CO2 concentrations have increased to nearly 390 ppm in the last 50 years by saying, "The oceans did it." You have to explain this in terms of something that did not exist 50 years ago (or was much smaller 50 years ago than it is now).

That would be . . . human greenhouse gas emissions.

Furthermore, when oceans absorb CO2 they form carbonic acid (the acid that you get in soda pop). The acidification of the oceans is harmful to the things that live there - particularly coral and shellfish such as oysters and clams. This is yet another cost of human greenhouse gas emissions.

SS400 said...

Hello. I've never posted here before, but I have been reading your essays of late, Alonzo, and I greatly respect your efforts to reason through morality as you do, so I thought I'd try taking part in some discussions and see where it leads.

I have a question about the reasoning presented in this post. You say that we should take precautionary measures to ensure that we avoid potential disasters despite the fact that we may not have proof that there is a disaster to begin with.

I think this works for just about any conceivable threat, though. If I, for example, say that giant, rabid, man-eating space hamsters will soon come to Earth and cause irreparable damage and suffering, does it not mean that we should take precautionary measures against the threat of space hamsters?

Despite the possible damage at the paws of the deadly rodents, would you not say that we should first have some sort of proof of this threat before taking any measure of effort to avoid extra-terrestrial death hamsters? It seems to me that this would be a case where saying "maintain status quo until there is evidence of deadly space hamsters" would be a reasonable thing to do.

I do not mean to say that those who deny global warming are right or wrong to do so, only that I'm confused by this particular line of reasoning because it seems somewhat suspicious. If I've misunderstood your point, I apologize.

Thanks for your time.

Eneasz said...

Supersage -

I'll let Alonzo answer on his own, but I want to note that for years he's been a strong proponent of establishing a human presence in places other than the earth's surface, precisely as a safeguard against extinction from an unforeseen catastrophe (such as a long-period asteroid).

Also of note, we already have a system in place to help guard against invaders, that being the military, altho so far those invaders have only been other humans.

It's nice to see so many new names commenting. :)

Alonzo Fyfe said...

I think this works for just about any conceivable threat, though. If I, for example, say that giant, rabid, man-eating space hamsters will soon come to Earth and cause irreparable damage and suffering, does it not mean that we should take precautionary measures against the threat of space hamsters?


Note, however, that the formula given says to take the amount of harm times the probability of harm.

What probability should we assign to the space hamsters?

I would say . . . less than 1 in 10 billion. So, even if the space hamsters (and the whole family of similar threats) threaten to do $1 quadrillion in damage, we can avoid the charge of reckless endangerment by spending at least $100,000 on this and all similar threats. I think that it would be quite easy to make the case that at least $100,000 in current activities is relevant to protecting ourselves from this threat. Therefore, we are already doing more than we need to do to protect ourselves from the charge of reckless endangerment.

Now, take a more serious threat - a significant asteroid or comet impact that could do $1 quadrillion in damage. With odds of 1 in 100 million, we are justified in spending $10 million protecting ourselves from such a threat. Less than that would constitute reckless endangerment. However, if you look at the money spent on programs to detect earth-crossing asteroids and comets and to study them, we are easily exceeding that amount.

So, yes, these considerations apply to all sorts of threats. More bizarre threats, or threats for which there is absolutely no evidence, are threats that we do not need to spend much to prepare for precisely because the probability of such a threat is so small.

SS400 said...

So, yes, these considerations apply to all sorts of threats. More bizarre threats, or threats for which there is absolutely no evidence, are threats that we do not need to spend much to prepare for precisely because the probability of such a threat is so small.

In this case, is it not entirely reasonable for skeptics to ask for evidence before taking more extreme precautionary measures against AGW? After all, if it is true that there is no evidence provided for such a huge threat, as they say, then it would seem their demands for evidence of the probability and scale of the threat before taking action to prevent it have merit.

This is not to say that there is no evidence for AGW. I only mean to say that the demand for proof is reasonable if we wish to say it's a huge threat that we should take seriously.

Alonzo Fyfe said...

In this case, is it not entirely reasonable for skeptics to ask for evidence before taking more extreme precautionary measures against AGW?

Evidence . . . yes, of course. If there were no evidence of asteroid impacts then there would be no sense in spending money averting them.

Furthermore, more extreme measures require a greater probability of harm to be avoided and/or greater harm.

However, one does not require "proof" in terms of certainty in order to justify action. As I argued, a mere 1% chance that a $25 trillion cost will be accrued justifies spending $250 billion in avoiding that cost (if it can be avoided for that amount).

But, yes, you need evidence of a 1% chance of a $25 trillion cost.

(As for Eneasz comments regarding my defense of space colonization, there is a 100% chance of the earth becoming uninhabitable at some undetermined point.)

John Doe said...

Personally, I'd like to see global warming alarmists put their money where their mouth is. Instead, I see them getting rich and living fat. Al Gore is the prime example. And the scientists are getting rich, or at least making a decent living.

I know that it does not invalidate their logic or their research, but I am a poor smuck caught in the middle. Many good arguments on both sides. Then I see people who claim it is a catastrophe living as though it isn't. All the limosines in Copenhagen, too. From the perspective of a skeptical observer, they don't act as though they really believe this. Yes, they want OTHER people to spend money and to scrimp and to do without, but they don't bother themselves. Doesn't that bother you even just a little?

SS400 said...

Out of curiosity, where does that formula, "money spent on precaution=probability of disaster * potential cost of disaster" come from?

Alonzo Fyfe said...

Actually, it is a specific application of a general theory in risk analysis.

How much should you spend on a ticket ticket that gives you a 1 percent chance to win $1,000,000?

The formula says that you should spend no more than 1 percent of $1 million or, in this case, $10,000.

Let's assume that you spend $9,000 - and that you play 100 times. In this case, you will (on average) spend $900,000 and make $1,000,000/

However, let's assume that you spend $11,000 per ticket. You play 100 times. On average, you will spend $1.1 million, and win $1 million.

The break even point - the point at which, playing 100 times, you will (on average) spend $1 million and make $1 million is determined by multiplying the value of the jackpot * the probability of winning. Or, in this case, $10,000.

This formula, which tells you the maximum you should spend to acquire a particular certain benefit, can also be used to tell you the most you should spend to avoid a particular future loss.

Anonymous said...

Alonzo, can you answer Lomborg's criticisms of your (or similar to yours) position?

Alonzo Fyfe said...


To the best of my knowledge, Lomborg has never criticized "my position."

Note: My position is that it is morally reckless and reprehensible to use clearly flawed arguments in a debate about actions and policies that risk the destruction of whole cities.

I have not, in these postings, defended any position on climate change itself.

As for Lomborg's criticism regarding political processes surrounding global warming, there are two criticisms to consider.

The first is his criticism of the science (where I share the opinion that his arguments were amateurish, flawed, and, at times, fraudulent).

However, he has a second point that is on a more solid footing - which is that each public dollar should be spent addressing those problems where we can generate the highest rate of return per dollar spent. Here, he argues that a sum of money addressing AIDS, malaria, and malnutrition can generate greater benefits than an equal amount of money spent addressing global warming.

These claims are consistent with the conclusion that, even though global warming will inflict huge costs, it takes a huge amount of money to avoid those costs. Whereas malaria (for example) also inflicts huge costs, but we do not need to spend nearly as much money to avoid those costs.

The principle that public money should be spent where it gets the greatest return on investment certainly has merit. And I am not qualified to assess his arguments as to which problems would allow the greatest return on investment.

However, in his most recent work he collected the opinions of a large body of prominent economists - which gives the conclusions more merit than if they were his own opinion given the poor quality of his own work.

Also, the Bill and Melinda Gates Foundation performed independent research on which charitable contributions would produce the greatest return on investment. They decided that it is more important to invest in fighting Malaria and AIDS in Africa.

So Lomborg, on this issue, may be correct.

anton said...

Current US history indicates that more than $200 million of tax dollars is being spent to stop flooding of Devil's Lake, North Dakota. It isn't a matter of global warming but it an example of gross economic stupidity and attempted international bullying (originally they wanted to pipeline their "excess" into the Red River system and "contaminate" most of the water system in Manitoba, Canada.

This "no outlet" lake has flooded regularly; caused untold damage; cost countless dollars; and the people keep rebuilding the town -- on a known "flood plain". Attempts to advise them that they better build again on higher ground was met with the what can best be described as "belligerent ignorant defiance". They have been championed as "tough" Americans who won't quit in the face of adversity.

Could most of the "naysayers" have been born in Devil's Lake?

SS400 said...

Spending $10,000 on a lottery ticket with a 1% chance of $1,000,000 return doesn't seem reasonable at all. Even if I would be likely to break off even playing 100 times, I'm only spending that much to play one time. That seems like a ridiculous amount of money to spend given the likelihood I'll win with that ticket.

Eneasz said...

Mathematically, you'll break even, so it's probably not worth the effort of buying a ticket. However if you could buy one for $9,900 you should always buy as many as you can assuming that losing will not bankrupt you. Assuming the lottery is drawn once per week, you'll be averaging over 52% APR, which is insanely better than any investment market.

If you can't afford to buy even one ticket, you should form a coalition with as many people as it takes and split the winnings among yourselves. It is free money. To not buy the tickets would be as stupid as not buying a dollar for 95 cents.

The only real problem is that this (almost) never happens in real life. :)

SS400 said...

Does everyone here spend hundreds or thousands of dollars on lottery tickets? I don't know anyone who would see that as a logical thing to do. Even if you had as much money as Bill Gates, I don't think it would be a good idea to spend so much on a lottery ticket. I might just be insane, but it just doesn't seem practical to spend so much to me.

Eneasz said...

Of course not, lottery tickets like these don't exist. The odds-to-cost ratio is always such that the house takes money from those who play. They're always something along the lines of paying $2 for a 1-in-100 chance to win $100. At that rate you are losing $1 every time you play (on average). That's why the lottery is often referred to as a tax on people who are bad at math.

But if a ticket such as the one presented in the hypothetical did exist, buying would be the best strategy.

SS400 said...

Yeah, I suppose that makes sense.

Andy said...

"This formula, which tells you the maximum you should spend to acquire a particular certain benefit, can also be used to tell you the most you should spend to avoid a particular future loss."

This only works if the person in question is risk-neutral. If the person is risk-averse (like most people), then it would be rational for him to spend more than his expected loss to avoid the loss.

Suppose you had a game where it's equally likely you'll win or lose $1 million. The person who only cares about expected value would be indifferent to playing this game. However, most people would not be indifferent to playing this game, I would not play. That's because I'm risk averse. The monetary value of the positive and negative payoff are the same. However, the utility that comes from each payoff is not the same. The positive utility from receiving the million is not the same as the negative utility in having to owe the million.

However, your general point still holds. Nobody, unless they are risk loving in this situation, should spend more than the expected gain to obtain a benefit. On the downside, nobody should spend less than the expected loss to avoid the loss. If someone is risk averse, they may very well spend more because there is value in avoiding the uncertainty.

One will certainly not pay money to enter into a fair game but they may certainly require payment to enter into a fair game (Here a fair game is one where the expected value is $0).

One other reference is the gameshow "Deal or No Deal." Often, the banker offers the contestant an amount lower than their expected gain. It is not always irrational to accept the banker's deal. Also, since it's a gameshow and the contestants can be risk loving, if the banker's deal is above the expected gain, they still may not take the deal.

Of course, this has nothing to do with global warming which is a case where we should be risk averse. Hence, we should be willing to spend at least than the expected loss due to global warming to avoid it.

Sorry this was so long. I took a course on probabilistic microeconomics where we studied these things in detail. Super interesting.

anton said...

Hi, Gang,

So lets get human for a moment.

"I am sorry, children, but it looks like most of our country will be wiped out by the flood, but your grandfather did a risk assessment and it didn't make economical sense to take the necessary steps to protect us! Lets hope that our boat makes it to friendly shores. I hear they are repelling all attempts to land our boats on their high ground."