In reply to Jed Rothwell's message of Thu, 12 Mar 2009 17:57:18 -0400: Hi, [snip] >At present, biological processes are not having a >significant effect on CO2 concentration.
They do have a significant effect. In fact it is larger than the effect we are having. However at present our effect is all in one direction - up. > >3. Our models of the atmosphere are increasingly accurate, as shown >by weather prediction (as I said). Weather prediction isn't accurate beyond about a week, and most of that is due to satellite imagery telling the weather forecasters where the weather systems are, and what direction they are moving in. > These models predict that >increased CO2 concentration should have already increased average >temperatures. This has been confirmed by actual measurements. True, but the models are also tweaked until they agree more or less with existing data, so this isn't really as impressive as it sounds. >The >models also predict that the problem will get worse in the future as >the concentration increases. Hey, I can do that in my head, without a computer. But it's still only necessarily true if the whole process is bound by the constraints taken into consideration by the models, IOW if they haven't left out any effects (and it's 100% certain that they have). >It is argued by skeptics that the models >are not dependable. They aren't. >That is not in evidence; they are working >already. See above. >It is argued that they cannot work because they are >extremely complex, but (as I said) they are no more complex than >models in other areas of science which are proven to work. We have been here before ;) > >4. Skeptics argue that the models are not reliable because they >describe phenomena on a large scale (a planetary scale). This is >faulty reasoning. The scale of a phenomenon has no bearing on whether >it is predictable or not, or whether it can be modeled or not. Correct. However the complexity of the phenomena upon which they are based does have a bearing. I think it's a safe bet that there are going to be a few surprises along the way. >Equally complex models about large-scale phenomena in nature such as >the behavior of stars and galaxies are reliable. I would argue that the number of different types of phenomena involved in astronomical models are less, and hence the complexity is less. >Going down a similar >number of orders of magnitude away from common experience, we find >that models describing subatomic particles also work quite well. ...which is why they predict cold fusion. :^) >There is simply no reason to think that models about the entire >earth's atmosphere are somehow unreliable because the Earth is large. Agreed. > >5. I reiterate that once the CO2 enters the atmosphere, the model of >what happens next becomes relatively simple, and it is well tested >and confirmed (unfortunately). ...but the point is, how long will it stay in the atmosphere. This can vary considerably, depending on how the biosphere reacts. To push the point a little further, consider that we are also part of the biosphere, and if we wipe ourselves out tomorrow, in a nuclear holocaust, then the CO2 levels may drop in a few years. Or perhaps a deadly pathogen will have the same effect. Of course in that case, there may not be anyone around to care, or there may be a few survivors. The point is, the future really isn't predictable. > >6. Perhaps some enhanced biological process may arise that removes >CO2: something like an unexpected plant bloom, or what Russ George is >trying to with iron oxide in the ocean. However, we cannot count on >this occurring. It would be foolhardy to do nothing and hope that >some biological process comes along and rescues us, or that some >beneficial feedback mechanism is already at work. Agreed. Even though the process is inherently unpredictable, we should act as though it were. (We should err on the side of caution). >Obviously there >will be some beneficial feedback and some plant blooms, but there >is no evidence that a sufficiently large beneficial feedback >mechanism exists. And there is some evidence that the opposite kind >of feedback mechanism may arise which makes the problem much worse. > >- Jed There is evidence for at least one type of biological feedback that would be sufficiently large:- Ebola. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html
