John Christy is a climate scientist at the University of Alabama in Huntsville (UAH) and the State Climatologist for Alabama. He was lead author on the IPCC's 2001 report on global warming, and is one of the few credible climate scientists who dissents with the scientific consensus exemplified by that report.
Christy's position seems to be as follows:
- Global warming is happening. (agreement with consensus)
- It is inconceivable that human activity is not one of the drivers of global warming. (agreement with consensus)
- However, he does not see global warming as a significant problem.
As such, Christy is a global warming skeptic since his final conclusion negates any necessity for action to mitigate global warming, despite not questioning the phenomenon itself.
Apparently the only argument he offers in support of his dissent is that of urban distortion of temperature readings, also referred to as the "heat-island effect" -- but this argument has long been debunked.
In the absence of any more credible arguments from Christy, he must be considered not just a skeptic but a denier.