Ozbib,
excellent.
Evolution has also been the subject of constant revision, though the fundamentals remain unchallenged, except by creationist loonies/intelligent designers. Off topic, I know, but there's an obvious parallel with those who deny the fundamentals of AGW. It should be changed to AGD (anthropocentric global destruction); warming is of course only one of the many related symptoms of the catastrophic human induced biospheric malady under way.
But no, there ain't no such animal, is there.

Q&A, GrahamY,

"The simple fact remains, those who are not trained in time series statistical analysis really don’t know what they are talking about when they state global warming stopped in 1998, or that the globe has been cooling since then." (Q&A)

I don't know anything about the court case, but I do know you don't have to be a statistics expert to sensibly interpret the temperature time series of the past few decades.

Bob Carter takes 1995 or 1998 as the start of his graphs, both relatively high years. See Fielding's graph (attributed to Carter) at
http://betternature.wordpress.com/2009/12/03/global-warming-not-cancelled/
If you just include back to 1980 or 1970 you see there has been an obvious increase, which Carter's version obscures.

There have also been temporary small decreases in the 5-year moving average - See
http://betternature.wordpress.com/2009/10/15/global-cooling-since-1998/
It is then obvious that the recent small decrease is nothing unusual, and no reason to proclaim the end of global warming. If it lasts another decade, then you'd have a case.

Also if you pick plots other than Hadley (which don't include polar data and so miss some of the more recent warming) you see the recent small decrease is less pronounced.

In other words, Carter cherry-picked the data in a blatantly obvious way. Either he's incompetent, or he's blinded by his cause, or he's flat-out dishonest. Sorry, but that's the straightforward conclusion.

Ozbib,

Nice discussion. I think there's a way to be even clearer. My own criterion for a theory is not "truth" or "proof" or "disproof" but whether a theory is *useful*. Thus Newton's theory had an inaccuracy, but it was still very useful. Einstein's theory was more accurate, therefore *more useful*. But Newton's theory is not therefore *wrong*.

Science is not about truth or proof, it's about finding useful guides to how the world is observed to work.

Well said, Geoff. One would assume that most OLO-ers could understand what you have written and would agree that "usefulness" is a useful way of looking at the scientific method. A similar approach is thinking of science as "reliable knowledge". For a good exposition see John Ziman's "Reliable Knowledge" (Cambridge University Press 1978).

"Proof" is also not an absolute, except in situations of constrained logic, like mathematics, where all the axioms and operations are agreed upon, so the "proofs" are just corollaries, or outcomes.

By thinking of "reliability", we can then ask "how reliable?", which leads into statistical probabilities and measurement uncertainties (unhelpfully called "error bars", which sets the deniers running) etc.

Thus, as statement about global warming such as "at the present trend, it is likely (ie a high probability) of a 2 degree global temperature rise within a century" is couched in terms of probability. One cannot "prove" global warming, as it is inferred from data. Similarly one cannot "prove" AGW.

And by the same token, one cannot "disprove" these things. The most that deniers can say is that the data correlations are not sufficient to give them cause for worry.

So it boils down to issues of "reasonable doubt", which assumes that all parties to the debate are reasonable.

Personally, I think the Copenhagen Summit killed any unilateral agreement on Carbon Emissions. I have heard beside Australia other
countries are following suit and not voting for Carbon Emissions
because of the doubt thrown up allegedly by Al Gore and now the anti
Al Gore et al movement denial that the science is flawed. And it is!

What worries me is that this will stop any movement towards greener energy and fuels, soil science technology to improve carbon sequestration, land use generally, not reduce the destruction of rain forests in South America and elsewhere, and other worthwhile sustainability measures.

I mean those TV ads in Australia on SBS - "Even if CO2 emissions tomorrow ceased, the methane from cattle, sheep are enough to continue
global warming. Save the Planet! Eat veg not meat". That's enough
to warn anyone interested in 'Saving the Planet' environmentally to
question the questioners.

In my opinion, wind generated electricity is a worthwhile venture,
provided as some critics suggest, that it can sustain small communities. However - like solar it is not been proven so far to
be able to exist without major problems, either by continuance of supply when there's no wind available, and if they break down, the windmills cost more to repair than to replace. And in cold countries
solar is not an alternative to nuclear or coal fired electricity plants. I am initially was against nuclear thinking about Chenobly
however, that plant was old, badly run, etc., and the newer plants
are less hazardous (So we are told?). Water driven plants or wave
geothermal, solar thermal even, might be an idea for the future, when
fossil fuels run out, and we aren't held at ransom by foreign oil producers.

Without any decent electricity supply we are gone!

Bugsy

It seems only others can use the 'metaphor', so yes … I do most humbly repent. The Supreme Court Appellate Judge Mackenzie did not use the word “crap”. He said:

“There was also reference to the period 1998-2006 which the Tribunal’s reasons describe as another example of a period of cooling. The year 1998, selected as the starting point for the period of cooling (in Bob Carter’s graph) was, according to the graph, significantly warmer than any of the years preceding it and any which had followed it up to 2006. Had either of the following two years been selected as the starting point, and the result for 1998 been treated as an aberrant spike, the period to 2006 would have demonstrated an increase over that period larger than the alleged cooling relied on by the President.”
_____

Geoff Davies http://forum.onlineopinion.com.au/thread.asp?article=9906#160445

"In other words, Carter cherry-picked the data in a blatantly obvious way. Either he's incompetent, or he's blinded by his cause, or he's flat-out dishonest. Sorry, but that's the straightforward conclusion."

The point I was trying to make - of course, you are right. If I say things like that I get threatened with suspension (if not banned altogether) or get rapped over the knuckles.

Have you seen these ‘Nature’ pieces?

http://www.nature.com/nature/journal/v463/n7279/full/463269a.html

http://www.nature.com/news/2010/100120/full/463284a.html

They are not 'pay-walled' and are worth a read, by everyone. Nonetheless, the ‘deny-n-delay’ brigade will no doubt cherry-pick and use them for their own agenda.
_____

Jedimaster

<< So it boils down to issues of "reasonable doubt", which assumes that all parties to the debate are reasonable. >>

Hmmm … thing is, science “debate” is not judged as in a court of law (guilty/not guilty) but rather on weight of evidence, by their peers.

Indeed, “debate” is rather a loose term when discussing scientific nuances. This is why it is ludicrous for (most) scientists to indulge in public debate with articulate show-ponies (those damn metaphors again) with an averse agenda, or people who only believe what they want to believe, regardless of the science.

Btw, do you know who is funding the Monckton-Plimer “road-show”?

Q&A

I've tried to find out who is sponsoring Monckton- it seems like it's ad hoc with Plimer helping. It would be nice to know- in the name of transparency- if their are any specific corporate sponsors.

John Ziman, to whom I referred in an earlier blog, once made the distinction between law and science as being "advocacy" compared with "evidence". Both Law and Science require the "facts" to be presented. With Law, the judge and jury weigh these facts on the scales of justice, which are calibrated according to "beyond reasonable doubt" or "on the balance of probability". As the tilting of the scales gives rise to "penalties" to one of the parties, there is great motivation to not disclose all the facts or use rhetoric, sophistry and other devices of debate to emphasise the subjective nature of the facts. In my experience as an expert witness, I found lawyers constantly promoting "remote possibilities" as "distinct probabilities".

Science, in its best practice, only talks about probabilities- leaving it to the reader to decide what course of action they should take, given the level of probability (or uncertainty) expressed.

In summary, it seems that we have a clash of cultures going on here- the "advocates", who seem to think that scientists are putting our modern lifestyle on trial, and for whom "anything goes" in their discourse versus the "evidentialists", who are hobbled by the ethos of science and are condemned for having less than perfect knowledge.