An Introduction to Global Warming

6/8/2010.

It is not a lie. The best evidence we have suggests that the globe overall is getting warmer. However, it may turn out to be incorrect. The warming we are seeing may be imaginary warming caused by things like the urban heat island effect.

Even the claim that emissions of greenhouse gasses is a significant factor in global warming is not a lie. Most likely, it is an apparently-reasonable but erroneous conclusion caused through a succession of scientific errors. The process began when good surface temperature data failed to correct for urban heat island and re-siting effects (where, say, a power plant was built next to a temperature monitoring station, causing it to read higher temperatures that don't reflect any change in climate).

Once the land temperature record was contaminated by these effects, the proxies that were calibrated to the land temperature record became likewise contaminated. If you want to measure temperature going back 1,000 years, you use things like tree rings. But how do you know what tree ring width corresponds to what temperature? Simple, you compare measure tree ring sizes for temperatures you already know. But if that knowledge is contaminated by errors such as those above, so will the tree ring data.

Needless to say, the contaminated data from the proxies and land record infected the computer models. There are a number of factors in the computer models that we do not know how to set correctly. So people tweak those factors until the models produce the right data for the past, then they run those models to predict the future. But if our knowledge of the past is wrong, the models prediction of the future will likewise be wrong.