We cannot experiment on planetary levels with climate over short periods of time. One need only look as far as the local weather forecast and how consistently inaccurate it is to see proof of this concept.
Add to this all the various weather stations that are set next to exhaust ports of air conditioning ducts, next to trash burning barrels, in areas near major airports where they are subjected jet blasts, tied to chimneys, and placed in asphalt parking lots, along with the complete absence of precipitation and it's effects on temperature in the models, and you have nothing more than fraud. I also read recently that many, if not most, of the weather reporting stations in the former Soviet Union were abandoned after the collapse and that loss of data has also not be included.
This "global warming" nonsense is like peeling back an onion. The deep you dig into the "facts" the more layers off corruption you find.....
The temperature measurements that they take from airports in cities where there is a heat island effect (like Phoenix, Tucson or Fresno) distort the numbers further...