New Mexico’s Supreme Court upheld an appellate court decision on GHG emissions sending the case to the State Environmental Improvement Board for resolution rather than have it play out in state courts. The high court also allowed an environmental group the right to intervene in the case brought by the state's largest utility and other energy entities, which seek to repeal greenhouse gas emissions rules. The action marks the latest in an ongoing battle over whether New Mexico should carry out greenhouse gas reduction rules. The GHG reduction measures were sought by Governor Bill Richardson (D-NM), who left office January 1 before the rules took effect. Governor Susana Martinez (R-NM) attempted unsuccessfully to block the rules from being implemented in January as part of a statewide review of new and pending regulations. When the courts ruled against her, Governor Martinez sought unsuccessfully to have the New Mexico Legislature undo the standards legislatively.