And, "global warming" is a meaningless phrase, and it doesn't cause cooler temperatures.
Well to some degree global warming has become a catch phrase. And since most people who use it to support AGW speculations have absolutely no idea how physical geographical effects are mediated, but are merely repeating things taken on faith from people who claim to understand, hearing that term is usually an alarm signal to me that the person using it probably has very little accurate knowledge about or workable understanding of the topic.
Several things must be kept in mind when discussing AGW. First it is not even a theory, it is a speculative conjecture. A theory can be tested by comparing predicted results to real results. And since no scientific "modeling" based on AGW ideas has ever successfully predicted real observations, it does not even qualify as a theory.
Another is that any discussion of "average global temperatures" must include the fact that reliable, consistently-accurate, durable thermometers did not widely exist until well into the 20th century. So any accurate global "temperature measurements" could not even have existed prior to that time. Science has to rely on much-less accurate means to determine average atmospheric temperatures prior to the deployment of accurate thermometers where the margin of error is often 30 degrees one way or the other!! The further back in history we go, the greater the average margin of error.
Even after thermometers were created which could accurately measure temperature, the placement of those thermometers by researchers or their assistants was often done haphazardly, stupidly or worst of all, to purposefully give misleading measurements.
For example, recent studies found that weather station monitors used in data gathering to determine average global temperatures have recently been set up on hot roof tops, near heat vents, on hot asphalt surfaces, in direct sunlight and other places which obviously do not give accurate atmospheric readings.
Urbanization is the effect when materials such as asphalt, which reflect solar heat back into the atmosphere instead of absorbing it, replace natural surfaces. In such cases, local temperatures have risen locally but not global temperature. The way they know this is that when a city such as say Boston added hundreds of square miles of asphalt in the form of roads or structural roofs, the average atmospheric temperature of the urban Boston area did increase slightly from previously measured levels. However, temperature in the immediate vicinity outside the city area did not increase, which means that the temperature increase was entirely local (urban) and that therefore it could not be correctly seen as "global warming".
Probably the biggest factor is that there may in fact be a time when average global atmospheric temperatures do increase. That has happened repeatedly as documented by the geologic record, long before human beings could reasonably be considered a possibly significant element of physical geography or mediation/distribution of black body radiation (solar heat) within the atmosphere.
There is a great deal of evidence which suggests strongly that the single greatest factor in warming of the planet's atmosphere would be variations in solar output and that this actually shows that a cycle of drastic cooling (possibly even another ice age) may be on the horizon. Until there is some testable, objective scientific evidence that shows conclusively that there is some causal link between human activity and significant average climatic temperature increases, it is logical to assume that any major changes in average climatic temperature are largely a natural phenomenon.
Therefore, arguably the greater and perhaps only prudent question for science would be how to ameliorate the EFFECTS of the warming not how to attempt to reduce the warming itself.
Last but not least, there are recent studies which show that any climatic atmospheric warming has had and will continue to have a net beneficial effect on the planet and on Humanity for some time to come. Far more people die or are harmed by insufficient heat/sunlight than by too much. More people freeze to death or starve because of cold-weather related crop failures or conditions created by cold air/water current shifting (el Nino, etc) than by warmth-related changes by a factor of many times. These same studies have determined that even accepting the average estimates of projected temperature increases made by AGW believers, atmospheric warming would not begin to adversely effect the planet or Humanity significantly for as long as two hundred years.
