2011-02-05 16:30:48Targeting the Guardian again - response to Spencer's gauntlet
Dana Nuccitelli

I put together something of a response to Spencer's challenge.  It's mostly just an excuse to talk about the evidence behind AGW, and what the global warming null hypothesis should be.  I tried to keep it simple in case The Guardian is interested in picking it up, so keep that in mind with feedback.

I had trouble thinking of a good title - suggestions on that front would also be appreciated.

2011-02-05 21:34:27
Mark Richardson
Show me one paper ruling out a teapot in orbit around Earth is what Dawkins would probably say.
2011-02-05 22:05:55


In your discussion on the null hypothesis, you seem to base the decision as to what to consider the null hypothesis on a public-safety issue.

I don't agree with this approach: 

- the decision as to what is the "default answer" is a matter of scientific/intellectual understanding, not related to implications of human welfare; the "precautionary principle" may be applicable to public policy, but not to scientific judgment.

- linking this decision to human welfare leaves you open to the charge of trying to decide matters of science on the basis of emotion. ("There must be a Higgs boson! Find it for the children!")

I think it would be better to stick to the basic point: How can Spencer take as a "null hypothesis" that mechanisms so far unimagined are responsible for phenomena that have a plausible justification in terms of "vanilla-flavored" climate science? Introduction of a new cause, particularly one without a specific mechanism, is by definition an extraordinary measure - one that requires extraordinary evidence. DISPROOF of the standard model, not merely arguing that the evidence is not strong or detailed enough, is needed to justify it.

2011-02-06 03:02:52Good point
Dana Nuccitelli

Good point Neal, I was having second thoughts about the public health discussion for that same reason. I thought it might work for a mainstream audience, but don't want to give the deniers any fodder. I'll revise it a bit.

Now I replaced the public health discussion with an explanation that the natural effects we're aware of can't explain the recent warming, while AGW can.  Spencer is proposing a new uncertain mechanism, so there's no reason it should be the default assumption.  It gave me the opportunity to link to a few other rebuttals and blog posts too.

2011-02-07 05:18:32anyone else?
Dana Nuccitelli
Any other feedback?  This is another one that would be good to strike while the iron on Spencer's gauntlet is still hot.
2011-02-07 05:53:44



If this is for The Guardian, I think it's much too dense. You're basically doing a rehash of all the scientific evidence for AGW, and it can't be done intelligibly in that short a space except to people who already know about it - who are not your target audience.

I think you can do this in two versions:

- Complex: Take this material and add more explanation to it, to make it more digestible. It will also be longer, which will cut down your audience; but at least the people that want to make the effort will understand what is being said. Maybe.

- Simple: Boil it down to the basic point: Spencer is trying to claim that an explanation that is consistent & compatible with all the physics and chemistry of the atmosphere that we know should not be accepted because not every conceivable - but not yet conceived of - theory has been disposed of in advance. He's asking that the default explanation - the "null hypothesis" - be that an unknown mechanism with unknown characteristics is the true cause of global warming.This is a ridiculous position to take.

A good scientist goes off hunting for an unknown mechanism with KNOWN characteristics when s/he's eliminated the known mechanisms: example: Wolfgang Pauli's demand for the neutrino to support conservation of energy on a microscopic scale. What principle is Spencer trying to support, that the AGW explanation offends? 

You could mention some of the reasons why we think that it's anthropogenic; but I would just allude to them (perhaps with links) and not try to explain them: That's done elsewhere.

2011-02-07 09:26:48Feedback
John Cook

It's dense but not opaque - you may get it in the guardian. I'd go for it. Just some nit picky comments:

"the theory that humans are causing global warming" - according to our style guide for technical jargon, I would change this to "our understanding that humans are..." to avoid the potentially confusing word 'theory' which means a different thing to the general public than it does to scientists.

This is contentious but I'd use heat in "scientists have measured the amount of energy being re-directed back..." Eg - "scientists have measured the amount of heat being re-directed back..." That way, you can say "climate sensitivity is a measure of how sensitive the climate is to this build-up in heat" which seems more intuitive than "energy change".

Is it too wordy to say "In every case we arrive at this same climate sensitivity range of 2 to 4.5°C with a most likely value of 3°C for a doubling of atmospheric CO2."

In the interest of gratuitous links to SkS, would it be too much to link the text "what we would expect to see from human-caused global warming" to http://www.skepticalscience.com/Stratospheric_Cooling.html

Ditto for http://www.skepticalscience.com/The-human-fingerprint-in-the-daily-cycle.html

Continuing my persecution of the word theory, how about changing "Conversely, the theory that human greenhouse gas emissions" to "Conversely, our understanding that human greenhouse gas emissions".

2011-02-07 09:32:16


Just a small irrelevant suggestion in the last paragraph

"Although we cannot disprove Spencer's "natural internal cycle" hypothesis, there is a very low likelihood that it is correct. " ==>

"Although Spencer's unspecified "natural internal cycle" hypothesis has not been explicitly disproved, it's unikely that it is correct. "

2011-02-07 10:08:52thanks
Dana Nuccitelli
Thanks guys, good suggestions.  Not sure if the Guardian will be interested, but I want to keep the post fundamentally the way it is.  It's mostly an excuse to summarize the supporting evidence.