(Part of the How to Talk to a Climate Skeptic guide)

Objection: The American Physical Society with tens of thousands of member scientists no longer believes that the science of global warming is conclusive. So what about that so called consensus?

Answer: The APS has not reversed its position on climate change:

Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate. Greenhouse gases include carbon dioxide as well as methane, nitrous oxide and other gases. They are emitted from fossil fuel combustion and a range of industrial and agricultural processes.

The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth's physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now.

This statement was reaffirmed on July 22, 2008 in response to a controversy prompted by the publication of an article by amateur climate skeptic Christopher Monckton. That article was published in the APS Forum on Physics and Society Newsletter, not a scientific journal, and is not peer reviewed science, nor is Monckton a scientist. The material Monckton presented has been thoroughly refuted by many working climatologists and the apparent embarrassment of the APS over how this happened has prompted them to preface that article with the following disclaimer:

The following article has not undergone any scientific peer review, since that is not normal procedure for American Physical Society newsletters. The American Physical Society reaffirms the following position on climate change, adopted by its governing body, the APS Council, on November 18, 2007: "Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate".

So, what about that consensus? Far from a skeptical institution, the American Physical Society is well in agreement with the IPCC consensus statement and their statement agrees with all the other endorsements from all the other major scientific institutions and national science academies from around the world. The consensus of scientific opinion on anthropogenic global warming is alive and well.

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Skeptic.

"The American Physical Society denies the so-called consensus" is also posted on A Few Things Ill Considered, where additional comments can be found, and where the author, Coby Beck, is more likely to respond.

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