George Monbiot has a great article this week citing DeSmog Blog, regarding the vexing issue of “trolls”. Not the kind that live under bridges, but those faceless cyberspace monikers that pop up frequently in comment sections of blogs likes this one, to repetitively froth away against climate science.

Are these real people? Or are they operatives in the employ of Big Oil? “Paul S”? “Phlogiston”? I’m talking to you.

It seems that Monbiot has same problem that we do. On the Guardian website, a small minority of anonymous “skeptics” often dominate the discussion by regurgitating talking points from well-known climate deniers. Sound familiar?

When Monbiot challenged his trolls to reveal their identity, or even confirm or deny whether they are posting from a PR office, he has never got a straight answer.

— gavin @ 8:00 AM

They don’t even notice the contradictions in their own cites. For instance, they show a figure that demonstrates that galactic cosmic ray and solar trends are non-existent from 1957 on, and yet cheerfully quote Scafetta and West who claim that almost all of the recent trend is solar driven! They claim that climate sensitivity is very small while failing to realise that this implies that solar variability can’t have any effect either. They claim that GCM simulations produced trends over the twentieth century of 1.6 to 3.74ºC – which is simply (and bizarrely) wrong (though with all due respect, that one seems to come directly from Mr. Gregory). Even more curious, Carlin appears to be a big fan of geo-engineering, but how this squares with his apparent belief that we know nothing about what drives climate, is puzzling. A sine qua non of geo-engineering is that we need models to be able to predict what is likely to happen, and if you think they are all wrong, how could you have any faith that you could effectively manage a geo-engineering approach?

Finally, they end up with the oddest claim in the submission: That because human welfare has increased over the twentieth century at a time when CO2 was increasing, this somehow implies that no amount of CO2 increases can ever cause a danger to human society. This is just boneheadly stupid.

So in summary, what we have is a ragbag collection of un-peer reviewed web pages, an unhealthy dose of sunstroke, a dash of astrology and more cherries than you can poke a cocktail stick at. Seriously, if that’s the best they can do, the EPA’s ruling is on pretty safe ground.

I took on law and poetry as fun; I took on environmental classes as work. As an Albertan with a keen interest in fossil fuels, good and bad, I wanted to understand the science, the truth, of global warming.

Ask the typical arts-educated journalist to read a science textbook and he or she will shriek or run from the room. I usually do both.

However, for months I buried my head in textbooks and technical reports in an effort to strip the discussion of global warming down to its nub–deprive it of emotion and hyperbole.

In the end, the hard science of human-created climate change is as convincing as it is unforgiving. You might as well be arguing against the science of evolution. Of course, that hasn’t stopped some people from trying.

Greenpeace members can get a bit strident in their opposition to industrial emissions–but do the science yourself and you’ll be fighting the urge to don a gas mask and hang protest banners from smokestacks.

Forecasts of polar bear populations and their likely responses to climate change have been strengthened by a new publication that refutes criticisms of the scientific basis for listing the polar bear under the Endangered Species Act.

The new paper, by a team of scientists from the U.S. Geological Survey (USGS), Woods Hole Oceanographic Institution (WHOI), University of Alaska, University of Maryland, Canadian Wildlife Service and the US Forest Service, refutes point-by-point a widely publicized critique of polar bear population predictions. The new rebuttal reinforces the reports written by the scientists and accepted by the Department of Interior in its May 2008 decision to list polar bears as a threatened species on the U.S. Endangered Species Act.

So let’s assume for argument’s sake that Mann, Bradley and Hughes made some terrible mistake in their statistical analysis, so we need to discard their results altogether. This wouldn’t change our picture of the last millennium (or anything else) very much: independent groups, with different analysis methods, have arrived at similar results for the last millennium. The details differ (mostly within the uncertainty bounds given by Mann et al, so the difference is not significant), but all published reconstructions share the same basic features: they show relatively warm medieval times, a cooling by a few tenths of a degree Celsius after that, and a rapid warming since the 19th Century. Even without Mann et al, we’d still be stuck with a “hockey stick” type of curve – quite boring.

So let’s try some more exciting “what ifs”. In mid-20th Century, medieval temperatures are exceeded in all the reconstructions, hence recent (last 10-15 years, say) temperatures appear to be unprecedented for at least a millennium (that even holds for the alternative histories presented by the “hockey stick” critics). Now what if that were wrong – if all proxy reconstructions as well as model simulations of the past millennium were fundamentally in error?

Let us assume that medieval temperatures after all had been warmer than the present. Even that would tell us nothing about anthropogenic climate change. The famous conclusion of the IPCC, “The balance of evidence suggests that there is a discernible human influence on global climate”, does not depend on any reconstruction for the past millennium. It depends on a detailed analysis of 20th Century data. In fact, this conclusion is from the 1995 IPCC report, and thus predates the existence of quantitative proxy reconstructions like the “hockey stick”.

I don’t like the cut of your jib.

“In the movie Inconvenient Truth we get to see Al Gore pondering deep thoughts while flying around in a private jet. Why not ride a bicycle? Why not write his charts on biodegradable paper and hold his lectures on camp grounds?”

This is the worst kind of argument. I’m almost at the point of refusing to talk to anyone who finds it to be a good one, but I realize there is some confusion about the status of ad-hominum arguments. In some cases, they are valid. For example,

“Frank told me he’d be a great little league coach. But, he does have those child sex abuse convictions.”

The critique of Frank’s character is relevant in this case, because it presumably would affect his motivations in wanting to become a little league coach.

“Frank told me I should buy shares in Exxon because energy is undervalued. But, he does have those child sex abuse convictions.”

The critique of Frank’s character is not relevant in this case.

But, these examples are cheap and obvious. What really is the difference? We really need to discern the different ways an ad hominum argument might be valid. Let’s look at a more difficult case:

“Greenspan thinks the most stable growth in the U.S. economy occured under the gold standard. But, he’s the cause of the current economic crisis.”

An Austrian economics would agree with both of these assertions (and find Greenspan a particularly strange figure for agreeing with a view and then acting in every way opposite to it). But more seriously, we might think that all of Greenspan’s economic knowledge is dubious because of his poor economic reasoning in the last ten years. But, and this is a very important distinction – this doesn’t prove his previous view is incorrect, it offers no evidence that it is incorrect, it simply offers a reason not to take it on authority.

Aha! But now we realize, that even when Greenspan’s economic knowledge was not in question, the mere fact he believed something is not an argument for its truth. This is another fallacy – appeal to authority.

So, when something about a man or woman’s character makes us question their motives, or their knowledge with reference to a particular field, this only reduces the strength of them as an appeal to authority.

But, to say “Climate change is true because Al Gore believes so”, is already a fallacy! It is appeal to authority! Climate change is real whether or not Al Gore thinks anything at all, he could clearly never have been born. Things are not true because we say of them they are true – rather we say of things that they are true because they are true.

So,

“In the movie Inconvenient Truth we get to see Al Gore pondering deep thoughts while flying around in a private jet. Why not ride a bicycle? ”

This kind of argument only appears convincing when we don’t realize that the kind of statements it calls into question are themselves already fallacious.

Amen, brother.