It seems logical to me and probably most people that scientists are going to be some of the most critical thinkers. And this is also their claim, but I am a little confused when it comes to discussions about climate change why so much critical thinking *seems* to be missing. I’ll explain what I mean.
I first have to admit that my knowledge of the science behind climate change is limited. I’m no expert. There are some interesting climate related things happening in the world so I can go along with the idea that maybe something is up, however, when it comes to proving that the changes are *all* due to the affect humans have on the planet, I become a big skeptic. I’m just not much into believing every alarmist and his impassioned story just because it plays to fears of global devastation (who doesn’t love a good Armageddon story).
Ok, so here’s what I mean when I say that the critical thinking seems to be missing. I’ve read parts of the IPCC Fourth Assessment Report on Climate Change. What is so striking to me is what terminology is used to express the certainty from this group that climate change is caused by humans (anthropogenic). Here’s what the report says in the footnote on page 4 of the Working Group Summary for Policy Makers (PDF), just so we’re clear on terminology:
In this Summary for Policymakers, the following terms have been used to indicate the assessed likelihood, using expert judgement, of an outcome or a result: Virtually certain > 99% probability of occurrence, Extremely likely > 95%, Very likely > 90%, Likely > 66%, More likely than not > 50%, Unlikely < 33%, Very unlikely < 10%, Extremely unlikely < 5%. (See Box TS.1.1 for more details).
Now maybe I’m just the dummy here and everybody else gets it, but I don’t understand how one can have such a high level of certainty when their assessment is based simply on using expert judgment.
In a court case someone who has knowledge in a particular field will be called an “expert witness” and their testimony will often be accepted as fact because of their knowledge and experience in that field. Ok, so I suppose we should apply the same thing here. We should simply accept that the people who have decided these things are experts and their judgment should be considered fact. There’s only one problem with that. The field we’re talking about is so new and unknown we would be foolish not to question the validity of anyone’s *expert* testimony on either side of the debate.
For those of you who are upset at this point because you feel I just don’t get it, please enlighten me. I don’t want a pointless debate. I want to learn and understand. On what basis do we blindly accept the testimony of these experts? Not only that, how is it that they can simply arrive at such a specific percentage of certainty? From what I’m told there are computer models out there that can demonstrate this certainty, but if that is true, then why don’t we see statements in the report that say “90% certainty based upon computer modeling and calculations”. Why do we just get, in essence, “90% certainty based upon some smart dude’s expert judgment”?
Does that sound like critical thinking to anyone? If you tell me to just blindly accept what these people say as truth, I’m going to have a hard time considering your position valid. It sounds like blind faith to me and as everyone knows, scientists cannot accept blind faith. They need critical evidence. Don’t they? Otherwise, isn’t this just a religious debate? If I said to an atheist, “I’m 90% sure that God exists because I’ve known him all my life”, he wouldn’t accept my testimony even though I’ve *demonstrated* that I’m an expert on God (e.g. I’ve known him all my life).
And while we’re talking about evidence, can someone explain to me how computer models are able to determine which molecules or particles in the atmosphere come from fossil fuels and which ones come from natural sources created by the earth itself? I understand that trends since 1750 suggest that it’s warmer now than it was then, but we don’t have much in the way of climate data prior to that date. Isn’t it possible that warming occurred at another time earlier in the earth’s history that was clearly not due to the industrial revolution?
Wouldn’t a stronger case be made if we could go up into the atmosphere and take measurements and be able to conclusively say “well, these particles over here are from Acme Manufacturing while these were caused by those gases coming from that volcano over there and there’s clearly more coming from Acme”? Do we have this kind of technology? If we do, then great. Let’s see the data from those tests.
Call me crazy, but I think the jury is still out on the actual certainty of whether climate change is anthropogenic. If you show me some evidence to the contrary aside from, “the expert is pretty sure–90% sure even”, then I’ll be glad to hear it. Meanwhile, lets stop with the fear mongering over something for which nobody seems to have absolute unquestionable evidence. Shouldn’t we require at least a scientifically *provable* (as opposed to arguable) level of certainty before we go requiring countries to reduce emissions to some arbitrary standard that may or may not make a difference even if the problem is caused by us?
Maybe you should watch “An Inconvenient Truth” I highly recommend it, of course it is biased but, and this you can get confirmed elsewhere if you like, there you can see what these theories are based on.
There has been done research on excavated ice cores that can tell very accurately how the climate was when the snow that made the ice fell to earth, the ice traps parts of the atmosphere and it is possible to calculate the average temperature the year the snow fell.
These ice cores show the climate changes for about 600.000 years back (yes that is supposed to be six-hundred-thousand) and this data is what these models are based on
Also you should read http://en.wikipedia.org/wiki/Climate_change and http://en.wikipedia.org/wiki/Global_warming these wikipedia articles explain these issues pretty well. Before you say so I know wikipedia articles can be inaccurate, but still there is usually a grain of truth in them and for the most part I think they are rather good.
You should start by watching “An Inconvenient Truth” http://www.imdb.com/title/tt0497116/ it explains some of the reasoning behind these predictions and theories. I know it is biased but still that does not make it untrue.
The basis for these theories is amongst other things research that has been done on ice-cores drilled from the ice on Greenland. When the snow falls it traps particles of the atmosphere in the ice and by studying these cores it is possible to see approxemately the average temperature and how much carbon dioxide (and other gases as well) the year the snow fell. These readings show how the average temperature was rather constant for a few thousand years untill the 1800’s
You should read these http://en.wikipedia.org/wiki/Climate_change http://en.wikipedia.org/wiki/Global_warming wikipedia articles as well, they describe these matters as well.
I started at Wikipedia myself, but for the same reasons went and found the actual references it cites. Probably the safest (i.e. most reputable) way. The issue still remains for me that saying “90% sure” is like saying “mostly sure”. There’s a lot hanging on “mostly sure”. I need numbers and I only need them on the part where they’re (the working group) claiming that people did it. ;-)
Thanks for the feedback. I’ve of course heard of Al Gore’s film, but haven’t watched it yet.
Just found this as I was looking around for documentaries on climate change: http://video.google.com/videoplay?docid=4499562022478442170&q=global+warming+swindle
Says that CO2 is affected by temperature–not the other way around.
Probably biased, but what isn’t?