Earlier this week, a story that CO2 climate sensitivity may be overestimated did the rounds.
The reaction by many climate skeptics / deniers has been more than a little triumphant, and you may be tempted to think this is reasonable. (Disclaimer: I’ll always try to distinguish between climate deniers – those that go out of their way to say the whole thing is bunk; and climate skeptics – those who have honest questions and may just be mis-/un- informed.)One of their major victory chants is along the lines of: Now they’re saying “it’s not that bad, we overestimated”, how can we be sure they didn’t ‘overestimate’ the whole thing?
There are a couple of problems with this. This is a preliminary study, it is the first of its kind. It’s the first to attempt to formally include paleoclimate data; most predictive models use only past climate records, as they are more reliable. (Minor aside – many climate deniers usually dismiss predictive mdoels out of hand as useless, but this one seem to be ok). All paleoclimate data is inferred in some way – by the widths of tree rings, by bubbles of gas in ice cores – and the date is not always known, so it is inherently less reliable. This study also only made one projection – the ranges of possible outcomes for temperature changes given in major studies (such as in IPCC reports) are based on several models all given different variables.
Because there are a lot of variables. This concept will have to be tested a lot of different times in a lot of different ways before the community can make any definitive conclusions – and that’s fine, because that’s how science works. There is no “they said this and now they are saying that” – there is no they.
Which speaks to another inherent problem especially prevalent in the denier community: that it is all some big conspiracy. The milder form in the skeptic community is that there is at least a tendency for negative studies (i.e. those weakening the idea of global warming) not to get published, and grants for the same are less likely to be granted. But this got published.
Not only did it get published, it received a lot of attention. Not only did it receive attention in the skeptic community and mass media, it received attention from the folks that like to go about saying this whole “climate change” thing is real and scary. And they’re not all running around going “Madness! We must cover this up and deny it or all our funding will be lost!” – in fact they are acknowledging a first reasonably robust attempt to incorporate paleoclimate data More studies on different models (as the BBC article says) will be needed to confirm or deny the conclusions, but really, the bottom line for me is this: Nobody is trying to shaft these results, these researchers, because it’s not the status quo. A possible change in our predictions has been suggested, now work will commence to either back it up or challenge it.
Talking with a classmate yesterday, she admitted to being untrustworthy of science because of the claim it has on the Truth. I tried to convince her that “science” never really does claim to have the absolute truth, just the closest approximation to the truth based on all current information. Which is the same as what we’re told any piece of good journalism is: the most complete version of the truth you have available at that time. I told her that it’s never actually “science” that says they have the ultimate truth – the media just often portrays it that way. I was sorry she had the impression that all science was arrogant, and that that was what she was led to believe, and that it wasn’t scientists’ fault because it’s not their job to clear these things up.
It’s my job.