I don't want to get too tangled up in this, but here goes
I agree the degree thing was a bit silly, but my point (as not-a-climate-scientist) is that it annoys the hell out of me when people go round shouting "no evidence, no evidence" and basically rubbishing the work of genuine climate scientists, who are working their arses off trying to get to the bottom of this.

A lot of the detailed predictions are based on models, which are of course problematic, but the basic physics of why CO2 affects the climate is simple enough. And you can calibrate the models - e.g. by taking the (known to pretty good precision) parameters of the atmosphere in, say, 1950, and running the model to "predict" what should be happening now. Which you can argue the models have been tweaked to do, so it doesn't prove much. More impressively, I saw a comparison between temperatures predicted by a model they ran in 1980, compared to what's actually happened since 1980. It fits surprisingly well.
Of course, as I saw it summed up elsewhere, if you don't think human-produced CO2 causes global warming, you need to explain two things: why the climate *is* warming up at the moment, and why the CO2 we're emitting isn't doing it, when basic physics says it should.

And... er, the evidence is kinda shouted from the rooftops. Most of the reporting in the popular media is appalling, as it is for pretty much all science, but that doesn't prove anything.

So, have you told your environmental scientist colleagues to their face, that you think they're wrong about the results of their work?
(julius, Thu 19 Feb 2009, 16:19, 2 replies)

too trusting?
Of course these scientists have no vested in interest in proving the hypothis right (continued funding) or no chance in getting it wrong (ice age predicted in the 70s).
(imp123, Thu 19 Feb 2009, 16:37, closed)

Just a quick one
the vested interest will apply either way - by that argument, the (oil/coal/car/cattle/pick your preferred evil empire) industry will probably happily give you research grants if your research points the other way. And seriously, even in the mainstream, if you have solid evidence going against the accepted view, it will be noticed and become accepted eventually. And you'll probably be famous for it.

And the 'ice age predicted in the 70s' thing is a bit of a canard, there was never any sort of broad-based agreement on that as there is now on climate change, not to mention that the science has become a lot more mature since then.
(julius, Thu 19 Feb 2009, 16:46, closed)

you mention the physics of it
CO2 is a tiny proportion of the earth's atmosphere around 0.04% if what I have read is to be believed.

My knowledge of physics inclines me to think that it can't have that much of an effect.

and yes I have told my environmental scientist colleagues what I think.
( Vipros. clever got me this far, then tricky got me in, Thu 19 Feb 2009, 16:41, closed)

As I saw in a different forum...
... if you think .04% can't have much of an effect, try injecting yourself with a tiny drop of 0.04% solution of Oxyuranus microlepidotus venom (er, whatever that is, apparently it's not very good for you). It's not a very useful analogy really, but the point is that tiny numbers can matter. Perhaps closer to the topic, atmospheric concentrations of CFCs were probably never even close to that, but ask the Australians how their ozone layer is doing...

As Ben Goldacre likes to say, I think you'll find it's a bit more complicated than that.

So how did your colleagues respond? Not saying this to prod you further, I'm genuinely curious.
(julius, Thu 19 Feb 2009, 16:51, closed)

a fair point about the tiny amounts and the ozone layer comment is well made!
that is based on chemistry though, rather than physics ;-)

as for what my colleagues say, it's kind of half split between them giving me looks of horror, as if I had sprouted scaly wings and horns, and ambivalence.

I need to reiterate though that I don't disagree that climate change is happening. My quandry is with the magnitude of the effect that humans are having on it.
( Vipros. clever got me this far, then tricky got me in, Thu 19 Feb 2009, 16:56, closed)

Okay, for physics rather than chemistry,
Ozone itself is at a concentration of about 2-8 parts per million (ppm) in the ozone layer. CO2 is about 380ppm in the troposphere. That small amount of ozone blocks almost all the UV energy from the sun. Trace gases, including CO2, have an effect. Fact.
(Stu Moo winner of five nobble piece prizes, Thu 19 Feb 2009, 17:51, closed)

That's not an appropriate comparison
The venom actively attacks bits of the human body. Continuing with the "ALL CARBON IS EVIL" thing, you'd be talking about Carbon Monoxide. CO2 is relatively benign.

I think bodyfat would be a more appropriate comparison; it's non-toxic- even beneficial- in a certain level.

Increase your bodyfat by whatever proportion we're increasing CO2 in the atmosphere and it's not that impressive a growth. It'll eventually affect your other bodily systems, causing catastrophic screwups. Limiting it is probably a pretty good idea, but only to the point where that limiting isn't having serious repercussions on your financial and mental state.
( uberdeity Wondered why Owen Lars knew of the term "hell" on, Fri 20 Feb 2009, 10:05, closed)