Sierra Club Executive Director Carl Pope plans to step down as soon as a replacement is found. After that, Pope plans to move into the role of chairman of the club and focus on climate change. He has been the head of the organization since 1992 and has worked for the club for more than 30 years.

"The Sierra Club Board of Directors has begun the process of forming a search committee and will formally launch the search for Pope's successor in the coming weeks," said a release from the group. Under Pope's leadership the environmental organization says it pressured the Bush administration to reverse its position against rules that would lower the amount of arsenic in drinking water and mercury in the country's fisheries. The group also advocated for no oil drilling in the Arctic National Wildlife Refuge.

                                                                                                                -- Winter Casey