This is not arguing from the evidence, though, but from a lack of evidence. Because we do not have highly accurate satellite observations of clouds, temperature, and the like over the last fifty years or more, any evidence for natural sources of climate change will require some digging to find. It’s like trying to solve a murder mystery when one has very little to go on initially. Since a possible weapon (greenhouse gas emissions) was found at the scene of the crime (warming), that’s good enough for the IPCC to pin the rap on humanity. One might think that the IPCC would have thoroughly investigated natural sources of climate change. But governmental funding of climate research in recent years has been channeled primarily into gathering circumstantial evidence to connect our greenhouse gas emissions to global warming. This is why you now hear every change in nature being attributed to manmade global warming. Scientists write proposals to receive government funding to study the effect that anthropogenic global warming has had on any number of natural phenomena. Is it any surprise if they find what they were paid to find? While a few government contracts, such as my own, are worded in sufficiently general terms to allow the investigation of natural sources of climate change, most are funded mainly because they support the current global warming