The American Physical Society (APS) has “overwhelmingly rejected” a proposal from a group of 160 physicists to alter its official position on climate change. The physicists, who include the Nobel laureate Ivar Giaver, wanted the APS to modify its stance to reflect their own doubts about the human contribution to global warming. The APS turned down the request on the recommendations of a six-person committee chaired by atomic physicist Daniel Kleppner from the Massachusetts Institute of Technology.
The committee was set up by APS president Cherry Murray in July, when the society received the proposal for changing its statement, which had originally been drawn up in November 2007. It has spent the last four months carrying out what the APS calls “a serious review of existing compilations of scientific research” and took soundings from its members. “We recommended not accepting the proposal,” Kleppner told physicsworld.com. “The [APS] council almost unanimously decided to go with that.”
The official APS position on climate change says that “emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth’s climate” and adds that there is “incontrovertible” evidence that global warming is occurring. The APS also wants reductions in greenhouse-gas emissions to start immediately. “If no mitigating actions are taken,” it says, “significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur.”
However, the petition’s signatories claim that “measured or reconstructed temperature records indicate that 20–21st century changes [in climate] are neither exceptional nor persistent, and the historical and geological records show many periods warmer than today”. They say that various natural processes, such as ocean cycles and solar variability, could account for variations in the Earth’s climate on the time scale of decades and centuries.