In this case, I think the error is in the vagueness of the question rather than the answer itself.
Human activity is probably a factor in observed climate change. This is why 97% of scientists “agree” but the question is not clearly asked, what percentage of climate change is natural and what percentage is human in origin?
As somebody very familiar with the field and its large community of members, I have the impression that most of this 97% would say 30 to 50 per cent is human. Some would say less, some would say more. So really it’s something like 97% who agree that part of the change is human in origin. I think the case is fairly easy to make that greenhouse gases are increasing and this would cause warming if there were no other factors (natural) at work.
The actual records seem to indicate that this warming may be a background component of a more variable trend and that the human factor has not exceeded the natural component.
This would not be a revelation in weather circles. The faulty impressions are more among the media and those who rely on the media for their information in the general public including political decision makers. But I think it’s true that for political reasons, many climate scientists are quite happy to maintain the ambiguity as a clearer exposition would reduce the political will for carbon taxes. Being left of center, these scientists figure that carbon taxes will somehow maintain higher salaries in the public sector. This is probably true for as long as the system doesn’t collapse under the weight of too many shall we say unsustainable assumptions.
Sure. Key word "observed".
The encroachment of construction and paved parking lots on instrumentation locations, including HVAC exhausts, and urban heat island effects likely cause an increase in readings compared to the past, prior to such construction.
The elimination of data points and the use of averaging also would be an artifact in the data set.
But those observational errors and artifacts do not mean humans are causing the planet to warm up.
Best post on this subject.