Reading the Lovejoy paper further, one part of the methodology struck me:
For the industrial era, Lovejoy’s analysis uses carbon-dioxide from the burning of fossil fuels as a proxy for all man-made climate influences – a simplification justified by the tight relationship between global economic activity and the emission of greenhouse gases and particulate pollution, he says. “This allows the new approach to implicitly include the cooling effects of particulate pollution that are still poorly quantified in computer models,” he adds.
Let me repeat that:
For the industrial era, Lovejoy’s analysis uses carbon-dioxide from the burning of fossil fuels as a proxy for all man-made climate influences
So not only does he uses a cold period as the base period to compare with, he also equals CO2 radiative forcing for anthropogenic effects and therefor, surprise, surprise, miraculously finds that man is changing the climate (because there is more CO2 in the atmosphere).
If this is what he really did, then it is no wonder that his conclusion is that humans change the climate. In my humble opinion he is wrong. His confidence levels shouldn’t be 99%, not even 99,9%. It should have been 100%. That would be the correct answer from his assumptions. He could have spared himself from doing all those calculations, he didn’t need all that mumbo yumbo to come to that conclusion. It is not really a conclusion, but just a rehash of the assumption he started with.