Discussion
There are a number of problems with this statement. The first sentence presents as a fact what is only a surmise. Although the evidence is strong that climate warming has anthropogenic sources, as described above,
anthropogenic warming is not a proven fact. Consequently, the wording in the first sentence “are changing the atmosphere” should have been “are probably changing the atmosphere”. In the second paragraph, the first sentence states that the fact of climate warming is incontrovertible, which is true. However, by its context this is
easily misread to mean that anthropogenic warming is incontrovertible. The only clue that there are uncertainties in the predictions for the global climate is the phrase “likely to occur” in the second paragraph. This hardly conveys the great uncertainties in analysis displayed in PSB. The paragraph as a whole has an alarmist tone that belies the underlying uncertainties.

So Mr. Bradbury do you disagree with the APS committee statement that, “…..anthropogenic warming is not a proven fact.”? Shouldn’t real science be based on proven facts?

http://climaterealists.com/attachments/database/APSAdHocCommitteeKleppnerReport.pdf

Your definition of “climate denier” is confusing. Was mankind responsible for climate change 130,000 years ago during the Eemian Period when according to ice core and sea floor sediment core data, the Earth was 5 degrees centigrade warmer than now?

Deniers are scientists, business leaders and academics who either deny the existence of global warming altogether or they deny that mankind is driving the climate and its subsequent change.

I recommend reading a book called “The Deniers” by Lawrence Solomon devoted to the topic. It is eye-opening and quite illuminating.

What is clear in the latest research is that too much focus was placed on man made CO2 and as a result many other equal or greater climate threats have been overlooked.

According to NASA scientists for example black carbon and atmospheric changes are the reason for arctic ice melt and that CO2 has been “insignificant” (using NASA’s actual word) with respect to arctic ice melt. NASA accepts that reductions in CO2 will not slow arctic ice melt.

The APS statement from 2007 was based on IPCC AR4 summary findings which have already been made weaker by the latest climate research findings, it is only a matter of time before they will have to revisit the 2008 data as Al Gore did and the 2009 data which Al Gore still needs to do, and then rewrite their position to better reflect climate reality.