Thanks for the moderation, Colibri. Your point of being faithful to the OP is well taken.
Having said that, the problem with being faithful to the OP is that the OP is ill-posed. There are varying levels of agreement (or skepticism) in scientists working in the field. This can be examined hierarchically, by examining the degree of agreement with the following statements:
*1. The earth is warming. *This is accepted by almost anyone in the field. There is general agreement that the earth has been warming for the last several hundred years, since the “Little Ice Age”. (Although there is also general agreement that we are at the cold end of the Holocene [the current interglacial], based on the ice core records, so it is equally true to say that the earth is cooling.)
2. Recent (20th century onwards) warming is unusual. Here, there is much less agreement. For example, the earth has not been warming for the last decade. Is this usual, or unusual? Is the 1920 - 1940 warming unusual? There’s not as much agreement about this general question. Overall, as Akasufo has shown, the planet has been warming on the order of half a degree C per century for several hundred years … which makes it harder to regard the 20th century warming of about 0.6°C as unusual.
*3. Humans are responsible for some part of the 20th century warming. *This one has general agreement, but the devil as always is in the details. How much of the warming is caused by humans? 5%? 95%? Somewhere in between? If you say 20%, are you a “global-warming-skeptic”, an “AGW supporter”, or neither?
*4. The main cause of the anthropogenic warming is CO2. *Again, even among those who agree that humans are the cause of some of the warming, there is not agreement on this one. For example, a number of scientists who agree with 1, 2, and 3 think that the main human effect is through land use and land cover changes (LU/LC), with CO2 playing a minor role. Others think that black carbon (soot) is the culprit, and this view has just received support in the latest Science magazine. So believing in AGW (anthropogenic global warming) doesn’t mean that you believe that CO2 plays a major role.
Thus, the question of “who are the global-warming-skeptic scientists” cannot be answered. Is someone who believes 1, 2, and 3, but not 4, a “global-warming-skeptic”?
“The improver of natural knowledge absolutely refuses to acknowledge authority, as such. For him, skepticism is the highest of duties; blind faith the one unpardonable sin.”
Thomas Henry Huxley (1907, Aphorisms and Reflections)
“I cannot give any scientist of any age better advice than this: the intensity of a conviction that a hypothesis is true has no bearing on whether it is true. The importance of the strength of our conviction is only to provide a proportionately strong incentive to find out if the hypothesis will stand up to critical examination.”
Peter Medawar (1979, Advice to a Young Scientist)
“I contend we are both atheists, I just believe in one fewer god than you do. When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.”
Stephen F. Roberts
“The skeptic does not mean him who doubts, but him who investigates or researches, as opposed to him who asserts and thinks that he has found.”
Miguel De Unamuno
*“For every problem, there is a solution that is neat, simple, and wrong.”
*H. L. Mencken
In the best of all possible worlds, all scientists would be skeptics. In the climate “science” world, it is used as a pejorative term … which is a sad commentary on the current state of climate science.