Ethan is a true believer in AGW, and has slipped in the usual bait-and-switch. He shows a graph that earth has warmed since the end of the Little Ice Age in the 1800s (which is not disputed), and then declares that the warming is due to humans and the effects of industrialization. However, the fact of warming does not imply any proof of any particular cause.
When physicists see an experimental result they hope for, like a spotty correlation between industrial activity and temperature since 1850, aren’t they first obligated to examine all the other reasonable explanations for the observation and demonstrate that they fail to explain the result, before they claim verification of their theory?
This is the first global temperature change ever that is claimed to be due entirely to human activity, not to the natural forces that have controlled the climate forever before. This amount of warming, quite small compared to many since the last glaciation, is certainly easily within the range of thousands of previous warmings (and coolings), all naturally caused.
To claim that the new factor of human activity is the cause, one must examine and discard those natural forces as contributors. To my knowledge, that has not been done.
Where is the proof that none of the natural forces alone or together can be the cause of this really modest warming, and therefore that human activity is the one and only factor that can explain it?
Aren’t Ethan and other Warmists arguing that it’s possible that manmade atmospheric CO2 is a contributor to the warming, therefore it is the dominant contributor, therefore natural forces can be discounted without need for proof, therefore the warming is due to humans and the effects of industrialization alone, therefore the warming will stop if those human effects stop? Would any physicist buy that kind of slipshod argument from another physicist in support of a new theory?