How do they know which is the cause and which is the effect?
Easy, globull warming causes everything from acne to cold weather to earthquakes.
How do they know which is the cause and which is the effect?
Not only don't they know which is the cause and which is the effect, they do NOT know if there is a cause and an effect. That is why these "global warming" "scientists" are not scientists. They mistake correlation for causality.
Here is an example of their illogic:
98 percent of Americans involved in traffic accidents had eaten potatoes within 24 hours of the accident. The conclusions of those nitwits would be:
(1) Consuming potatoes causes traffic accidents.
Banning the consumption of potatoes will save billions in damage to automobiles and about 41,000 American lives on the roads each year.
You end up with nonsense like this when the schools stop teaching scientific principles and methods and start teaching the religion of Al Gorism.