All this hooey ignores the number one reason for increase or decrease in global temperatures worldwide, which has NOTHING to do with anything humans are doing.
Its called the SUN which is the source of all warmth the earth receives. It naturally goes through warming and cooling trends giving off more and less energy... The sun is currently increasing its output... which means more heat for us... This trend will end and less energy will reach the earth daily and the planet will cool again...
Going around and looking at how overfarming the land in mesopotamia caused civilization to collapse there is hardly evidence of man caused world wide warming or cooling of the planet.
Water molecules in the upper atmosphere have more direct impact on global heat absorbed/reflected/retained than any C02 nonsense.
C02 is PLANT FOOD.. its not something that's going to turn the earth into an oven.
The Role of the Sun in 20th Century Climate Change
Final sentence of the introduction:
"However, assessments of the amount of energy coming from the sun shows no overall change in the second half of the twentieth century."
Read the rest and see if it's informative.