Wednesday, June 15, 2011

Correspondence with an AGW sceptic

Today's I am firing emails to anyone I can find, regarding the refutability of the AGW sceptic's position. 

I've had a further exchange with Benny Peiser, continuing from this post:

Benny says:

As an agnostic on the theory of anthropogenic global warming, I do not
hold a position that can be refuted. I am completely open-minded in this
respect and guided in my assessment by empirical evidence, not by computer

Perhaps I should return your question and ask you: what evidence would be
required to falsify the theory anthropogenic global warming?

With best regards

Benny Peiser 

To which I reply:

We are discussing a matter of science. Agnosticism relates to religious belief.

You have taken a position. If your position is scientific, it must be refutable.  If it is not refutable, it must be a matter of belief or ideology.

In a spirit of helpfulness, I suggest that your position is that climate sensitivity to CO2 is less than 1.5*C.

If not that, then what is your hypothesis?

Regarding computer modelling, would you be safisfied if the calculations were carried out by hand, as they were in the pre-computer days?

I am prepared to list the conditions that would refute our position, and will share them when you have provided your refutable hypothesis.


On 15/06/2011 12:43, Benny Peiser wrote:

You say that I have taken a position. Would you be inclined to tell me
what that position is? I certainly have no position on the thorny issue of
climate sensitivity which is a contentious issue among climate scientists.
 Neither do I adhere to any other hypothesis.

Yes, the emission of greenhouse gases have a warming effect. But the magnitude and speed of this warming remains uncertain, as does the extend
of natural factors that compete and may even eclipse anthropogenic global

With best regards

 Benny Peiser

To which I have replied:

It is odd for me to have to inform you what your position is.

It seems from what you have said that your position is that anthropogenic GH gases do not have a significant effect on global climate.

If your position is scientific, there must be a testable hypothesis underlying that position. I am trying to help you define that hypothesis, in order to define what set of observations  would be effective in refuting your hypothesis, and thereby confirm scientific status for your statements.

All parties to this debate accept that there are several other factors influencing global warming, including the sun, volcanoes, ocean currents and albedo.

Uncertainty is inherent in all science, and is managed by providing ranges in all figures.

I note that you accept that GHGs have a small warming effect rather than a significant one. To arrive at that conclusion, it seems that either you reject the basic physics of CO2 and infra red radiation, or the extent of increase in anthropogenice CO2 and other GHGs is less than generally agreed, (both of which would demand major revisions of science) or that your hypothesis is that the climate sensitivity for CO2 is much less than is generally agreed. I'm trying to help you here. Is that your hypothesis? If not, what is it?

If there are no facts that could refute your contention that human emissions do not have a significant effect on global warming, your contention cannot be considered scientific, and would therefore fall into the realm of ideology.


(Dr) Richard Lawson

To which Benny Peiser wrote: Dear Mr Lawson
I'm afraid your's isn't a scientific but a political response. What you are suggesting is that governments should act now, regardless of the potential cost to our economies - and act before we are able to confirm the magnitude and speed of any CO2-induced warming. The problem is that we don't know whether the diagnosed fever is serious, moderate or nothing much too worry about (at current low levels). I guess that's at the bottom of the political stalemate - but it is not a scientific validity test. That, I'm afraid, will take quite some time. With best regards
Benny Peiser

My response:

 Dear Mr Benny Peiser

The vast majority of atmospheric "doctors" are persuaded that the condition is serious and needs treatment.

The small but influential lobby of which you are an important member denies the seriousness of the situation.

The scientific debate precedes the economic decisions.

Our case is scientific, i.e. refutable.

It seems from our discussion here so far that your counter arguments have no scientific status, in that they are not refutable by observation or experiment. You are reluctant to put forward a testable statement of your case.

The nearest you have come to such a statement is the assertion that the effect of CO2 is minor. This can readily be translated into the assertion that the climate sensitivity to CO2 is small, perhaps less than 1.5*C. Such an assertion could be tested. Are you prepared to put that forward as the testable core of your case? If not, what testable statement would you prefer?

If you choose to refrain from any such testable statement, if follows that your case is not scientific, but ideological.

Your argument below is consistent with an ideological case, and can be formulated as follows:

  1. The idea of the free market must be supreme in all economic matters.
  2. A transition from carbon-based and finite fuels to renewable energy would require interference in the workings of the free market.
  3. Therefore the science that drives that requirement must be incorrect.
I hope that we can at least agree with this formulation?


Richard Lawson

On 16/06/2011 10:29, Benny Peiser wrote:
Dear Mr Lawson

I'm afraid hardly anything you allege reflects my own thinking.

You seem unwilling to engage in an open-minded dialogue and seem more
interested in attacking positions that I do not hold.

I regret that you seem unwilling to engage in a genuine debate which
doesn't surprise me given that you are a self-proclaimed Green Party
activist. I suggest that we call it a day.

Yours sincerely

Benny Peiser

To which I replied:

Dear Mr Peiser

If I attack positions that you do not hold, it is because you have been unable to articulate your position, actually inviting me at one point to tell you what your position is.

The bottom line is that you have been unable or unwilling to put forward a testable scientific hypothesis.
Your case therefore does not have any status as science.

I am grateful to you for continuing the debate thus far.

Hopefully this debate will receive more general attention in the coming months.


Richard Lawson


@jessecusack said...

I'm sure Benny trusts in computer modelling to design planes which can fly and predict the weather for the next few days.

Climate modelling uses different equations but its limitations and error margins are well understood.

I would highly recommend reading this article: , because there are problems with climate science but not the ones most people think of.

DocRichard said...

Thanks for the link, Jess. A useful review of the case.

Notice that Benny did not answer my q on whether he would accept it if the calculations were done by hand instead of by computer. I imagine that his answer would be "yes", in keeping with the general strategy of delay.

Flash said...

I think you are doing 'Benny' a dis-service here.

His stance appears to be that a mere mathematical model (whether done by a computer or by hand) is not a proof.

We do not 'rely' on computer models to design planes. The omputer models assis us to design planes ... but we then test the actual plane design in reality (a lot) before we ever fly in it.

And we cannot really rely on computer models to predict the weather even over the next 24 hours with any degree of accuracy. The systems are just much too complex ... as evidenced by failure to predict the weather conditions, wind, fog etc. on my most recent Channel crossing. Sometimes, the weather is indeed, as predicted by the model ... sometimes it varies a lot. Our weather models are essentially experience-based, they take observations and then based on some course theories and previous experience in similar circumstances predict short term behaviour (not all that accurately).

Climate models are even more distant from reality.

Coming back to the plane example ... we can test our models against various samples (eg, a brick, a wing, a paper bag and so on) and verify the model.

With weather (and in particular climate) there is no comparison possible ... we only have one sample.


DocRichard said...

Hi Flash
Proof belongs to geometry, not science:

Do not confuse weather and climate:

The models are not perfect (nothing is perfect) but they are a useful tool, and definitely quicker than doing the calculations by hand, which is what they used to have to do.

By all means let us make sure the models are properly used, and updated as new data and understandings come in, but the blanket rejection of models is irrational and anti-scientific since models are an integral part of all scientific enterprise.