I suggest that you ask someone who is "in" on the consensus to explain global warming in detail.
Have a few facts, like the changing "data", the model assumptions(water vapor causes the bulk of the heat retention), and the list of consequences(they are all "bad").
When you get finished talking, they will conclude that this isn't science, but risk attenuation, and a method to limit non-renewable resource use. If they are leftist, they will also conclude that it the use of such concepts, fake or not, is what spurs society forward, and will compare it to the Apollo project.
When you point out that such concepts are fundamentally fascist, they will get mad.
I've been through this cycle dozens of times, and it comes out the same every time.
I have been interested in this since the 90's, and have tracked the noaa reported data for my local weather stations since then. The change in our local stations has matched the "warming" reported by noaa within 10%. The fudging of the underlying data would be comical if it wasn't being used for imposition of fascist ideal onto our country.
By "change", I mean that they have changed the historic data as has been deemed necessary to make it look like global warming has been occurring. My conclusion is that the underlying data is so corrupt that it is essentially unusable for decision making processes.
Originally Posted by kehaar
This is how I think a climate simulation program works. First you divide everything from the crust of the earth up to the upper atmosphere into cubes, or more accurately three dimensional rectangular cells. How small the cells will be will depend on how much computing power you've got. Maybe they're around 300 miles wide by 300 miles long by 10 miles thick -- I'm just picking that out of the air.
From physics and engineering, you have equations describing three types of "transport phenomona" between the cells,
1. Fluid flow, that is, the movement of air (in the atmosphere) and water (in the oceans) between the cells.
2. Energy transfer, the absorption and emission of heat and radiation between the cells
3. Mass transfer. You construct your cells so that boundaries between cells exist along interfaces between ice sheets and air and between water and air. And you have equations describing the transition from ice or water on the earth's surface to water vapor. And maybe melting of ice sheets to water, I'm not sure.
You assign properties to each of the cells. You have to handle things like clouds. Also, as Dilbert and Jim have pointed out, probably things like volcanic ash and pollutants that may cause temperature to go down.
Next get a history match, where you use historical values for your inputs and see what the results are in terms of the calculated temperatures. If your simulation program can't match historical temperature, your simulation isn't worth shit. You need to go back and vary your inputs, and maybe your methodology.
Once you have a history match so you can have some confidence in your model, then you run the simulator, varying inputs like the CO2 level and perhaps other greenhouse gasses and pollutants, and you see the effect on temperature.
Does it work? I have "0" experience with climate modeling, but do know something about fluid flow. I worked on problems involving movement of fluids over areas much, much smaller than the earth, maybe a mile by two miles. Once I was asked to model a project that involved both fluid flow and mass transfer. The only way to solve the problem was with a simulation program. Without it there was no way you'd have any idea whatsoever of what was going on. And the earth's atmosphere is so much more complex. You have so many unknowns, so many variables, that you can't know whether global warming is real or not with simplistic models. If you do the simulation and get a good history match, all the while using a methodology based on the science and good input data, then you should have a very good idea of whether or not carbon emissions are contributing to global warming. You won't "know" the answer with 100% certainty though.
Looking at temperature data since the 1990's for one location isn't going to tell you anything. Global warming will likely cause certain locations (some of the cells) to get cooler, and the better simulation programs should show that.
For most or all of us, thinking we know the answers to global warming is a huge exercise in self deception. If you've got a PhD in physics and are willing to spend several months solid studying this, then yeah, you've probably got a fighting chance. Otherwise forget it. You're not going to find the answer by watching Fox News or MSNBC.
With respect to how the level of carbon emissions may effect global warming, we're kind of like Roosevelt was when he was deciding whether to pursue the Manhattan project. He had to rely on the experts.
What should we do about carbon emissions? That's a whole different story. The climatologists don't have a good handle on the effects or their magnitude. My suspicion is that cutting way back on emissions isn't going to be worth it. We'll be spending much, much more than we'll get back. But I could be wrong, I don't really know. My optimism is based on what Bjorn Lomborg, a statistician who's studied the economics of global warming, wrote. And I've read some criticisms of his work that make me less confident about this than I was.