Originally posted by: CycloWizard
I think you're missing the point. What you don't seem to realize is that, at some point along the line, ICE engines were designed using qualitative models with a side of hand-waving. Only the advent of computational flow dynamics methods have allowed quantitative modeling of engine behavior, and these were not available until very recently. Obviously we understood the basic workings of the engine, at least in a qualitative sense, based on age-old thermodynamics. However, fine-tuning to get those last bits of efficiency and power required better computational techniques and more power. Modeling the weather is no different except that the system is many times more complex because of its inherently chaotic nature, larger scale, and increased number of factors that must be considered in the model. Modeling the weather can, in principle, be achieved exactly using Navier-Stokes equations. However, solving these equations in a differential sense on a global scale is computationally infeasible to say the least, and will remain so for quite some time. In the meanwhile, qualitative modeling efforts give results that indicate possible causes for some observed trends in the data.Originally posted by: Skoorb
Well, you could say we don't understand internal combustion engines, but I use one to get to work and I bet it works an awful lot better than the tripe the weatherman told you this morning about what the weather will be like 10 days out Certainly you appreciate that we are more knowledgable in some areas than others. IC engines we've been successfully mastering for a long time. Weather, nope.
Qualitatively similar studies are meaningless. If I invest money into a savings account vs a lottery ticket and win I've qualitatively reached the same thing (made money). We don't understand this issue. That doesn't mean we can't try and do something to ward off a worse case, but to pretend like this is all so obvious and locked down is just plain wrong.
Actually, we do know pretty much what the human contribution is using the approach I mentioned above. Instead of trying to solve the local differential Navier-Stokes equations, they may be solved in an integral sense. In this case, the properties of the atmosphere are averaged together to give the net effect. If I solve the model with carbon dioxide levels at 100 ppm and again at 200 ppm, the results are significantly different. 100 ppm to 500 ppm gives a much larger difference. In fact, just this simple approach that most engineers (at least chemical ) learn in their first transport phenomena class can give nearly quantitative results for energy accumulation, which is amazing given the simplicity of the model. The problem is not that the individual contributions are not well understood, it's that laymen don't understand the methods used to arrive at these conclusions and so they do not make the news.The trend at this point is that we're getting warmer, that's true (exceptions notwithstanding). But, we don't know how much is because of us, we don't know what the net effect (gain/loss) will be, and sadly most of all, we won't do a damn thing to stop it becaus we are too greedy and short-sighted, and that's not just because of "people like me". I merely observe humanity through history and know that it's consistently f**ks things up even when it is obvious what's going on (heck, look at a fat smoker, they do it on a personal level, even).
Except that the warming in the troposphere (where all the CO2 is) doesnt scale with predictions.