I like Roger Pielke, Sr. He seems to be earnest and honest in his efforts as a climate scientist. Even though he is not a global warming skeptic, he has been willing to point out many times where alarmist advocates have gone off the rails and adopted bad science. Because of his honesty, alarmists view him with deep suspicion. They can't control him or keep him on message.
However, he has always had a very simple-minded approach to the science. First, he seems to worship the peer review process and seems totally unwilling to come to grips with the reality that it is a complete failure as a method to assure quality. He's never addressed the extraordinary number of flawed studies or the fact that similarly high percentages of flawed studies have been demonstrated in other scientific fields.
An example of the second problem is demonstrated in his answer to this question from a group of retired NASA people. He gives his opinions in answers to their questions, but it is obvious that he fails to understand the questions. When they ask about human influence on climate, he says it is obvious -- look at the increase in carbon dioxide and the increase in aerosols. But that isn't their question. They want to know if the climate is affected in any significant, material long term permanent way by human impacts. We all know that humans make initial changes in the climate. Every building, every farm, every fire ... everything humans do will cause a reaction in the system that would not have been but for the presence of humans.
The essential question is all about how the climate system responds in terms of permanence. After all, all kinds of changes in radiation from the sun and from other bodies in space also make initial changes in the climate. As can meteors and other impacts from space. We also know, however, that the earth appears to have a number of different mechanisms in the climate which tend to return it to some equilibrium. History shows that enormous volcanic eruptions can cause massive disruptions in climate all around the world which can last longer than a year. Yet the earth eventually processes the extreme disruption and returns to a normal climate state relatively quickly (in earth terms).
So this is the real question. Perhaps it would be easier for Pielke to understand if the NASA group asked him how discernible in our present climate are the impacts of major volcanic eruptions of the past. I suspect he will say he has no idea. And thus we know the answer to the NASA question. Humans make initial changes in the state of local climate. What is the long term impact and how well does the climate return to 'normal'? Neither he, nor anyone else, knows. But negative feedback toward normalcy is certainly a huge factor.