washington u.s. president donald trump administration prepare release wide-ranging executive order reduce role climate change play policy decisions accord trump administration official review draft order move could alter u.s. agencies weigh regulations broad array industries drill coal mine auto manufacture refine official tuesday confirm bloomberg news report executive order instruct environmental protection agency agencies overhaul use social cost carbon obama-era policy seek quantify potential economic damage climate change purpose draft regulation white house spokeswoman kelly love decline discuss time executive order energy nothing announce time say rule put place former president barack obama current cost carbon policy decisions 36 per ton rise 50 2030. trump order would direct regulators use discount rate would dramatically reduce eliminate cost discount rat use come net present value something whose benefit cost distribute time case carbon impact emissions earth climate take several years appear scenarios reference executive order carbon could zero negative value source say source say order may initial step ultimately phase carbon evaluation entirely executive order could issue soon week source say may include energy-specific measure like requirement epa conduct review regulations could harm energy production reuters others report previously trump plan target obama-era green regulations include federal coal mine ban initiative force state cut carbon emissions department interior obama issue moratorium coal lease federal land 2015 seek review program evaluate whether government adequately price value coal extract public land behalf taxpayers clean power plan obama centerpiece initiative combat climate change require state slash emissions carbon dioxide never implement due legal challenge launch several republican state new head environmental protection agency scott pruitt say last week convince carbon dioxide human activity main driver climate change say want congress weigh whether co2 harmful pollutant regulate obama administration carbon cost estimate first issue 2010 use analyze rule directly target carbon dioxide emissions like car truck emissions standards also use cover rule indirect emissions like one control mercury air pollutants power plant trump roll back use climate change policy review source