It seems that the American Association of Petroleum Geologists is softening its former hard-line stance on global warming.
A new proposed position paper  on their site contains a lukewarm acknowledgment of the role human activity and greenhouse gas emissions from fossil fuels plays in the present warming. They state:
Humans, simply by virtue of the size of the world's population, represent a new agent of change through our significant modifications related to land use, urbanization, industrial activity, and through changes in atmospheric composition related to fuel combustion and deforestation."
Not an outright acknowledgment, but a start when you consider their previous climate change position. Thanks to the wonderful waybackmachine  internet archive you can find the AAPG's position on climate change at least up to August, 2006 here. 
The former position was a well-couched outright denial of the realities of human-induced global warming. To quote:
One of the most contentious debates in American public policy today encompasses proposals to restrict emissions of the minor atmospheric gas carbon dioxide in order to mitigate a perceived human influence on global climate.
Detailed examination of current climate data strongly suggests that current observations do not correlate with the assumptions or supportable projections of human-induced greenhouse effects."
Human-induced global temperature influence is a supposition that can be neither proved nor disproved. It is unwise policy to base stringent controls on energy consumption through taxation to support a supposition that cannot be substantiated."Encouraging step forward for the AAPG, and one less place for the small pack of global warming deniers to hunker down.