I just sent this brief note to a fellow who blames mankind for global warming, and asked him to refute all or any of it. No reply, as yet …
* we are now living in an inter-glacial age
* the planet has been warming and cooling for eons
* the medieval warming lasted about 200 years, and was far warmer than today, even though that was a pre-industrial age
* no one can say for sure whether a rise in CO2 produces warming, or natural warming produces a rise in CO2
* CO2 is a friendly gas and more of it is welcome. People confuse it with Carbon Monoxide (CO). More CO2 produces more crop growth, and hence more food.
* the polar cap has always advanced and receded due to many natural factors not man made, such as warmer ocean currents
* there is no imaginable cause that could melt the polar ice cap, which has an average annual temperature of -26C, nor the antarctic ice cap, which has an annual average temperature of -51C.
* if all the ice that is floating at the polar cap were to melt, sea levels would not rise one centimeter (see: Archimedes Principle)
* natural factors that seriously affect earth’s climate include increases or decreases in solar radiation
* solar radiation may be the cause of global warming, if in fact there is any. A clue? – there has been recession of the ice caps on Mars, where there are no people and no CO2, but Mars is exposed to solar radi
* even the IPCC says the global temperature has risen a little less than 1 degree C in a century. A century! Even if accurate, which is debatable, what this would signify is an incredible stability in global temperature over the past 100 years
* instruments used for measuring temperature are not reliable, as too many of them are surrounded now by asphalt urban “heat islands, and so scientists have to “adjust” for this artificially-induced warming in their models. The adjustment made is … a crap shoot.
* America and Canada and most of Europe are peppered with measuring devices, but there are huge areas of earth – millions of square miles of land and ocean – including millions of square miles in northern Canada – which are not. Another crap shoot.
* no one can explain why the upper atmosphere seems to have been cooling, not warming
Oh… one more point. Volcanoes are bad news. Mt Pinatubo alone put more greenhouse gasses into our atmosphere than did the entire industrial revolution