From now on, every government agency will have to consider climate change

The new guidance from the Council on Environmental Quality will ask agencies to not only include climate change in these considerations but actually quantify the climate impacts of their decisions, when possible, in the context of the environmental reviews that are already required by NEPA. 

 The guidance also directs agencies to consider not only direct emissions of a project but also the “indirect” emissions. So, building a new road might encourage more people to drive, leading to more vehicular emissions. If agencies really can’t quantify the carbon consequences of their actions — if, for instance, there simply isn’t a legitimate scientific way of doing so — then the guidance recommends that they conduct a more “qualitative” analysis instead, and explain their reasoning.