Proponents of hydraulic fracturing point to the economic benefits from vast amounts of formerly inaccessible hydrocarbons the process can extract. Opponents point to potential environmental impacts, with some critics acknowledging that some fracking operations are far cleaner than others. (AP Photo/Brennan Linsley) The Obama administration has taken its biggest step yet to regulate fracking on federal land by imposing new environmental safeguards on the technique that has turned America into a shale energy superpower and upturned global energy markets. In a move that will be closely watched by other countries debating shale development, the administration said on Friday that it would introduce new rules […]