In 2011, Syncrude Canada requested independent review of the regulation that requires two percent of the content of all its diesel fuels to be renewable, even what it produces for its own use. Syncrude took the case to court when Environment Canada and Climate Change Canada rejected that request, arguing that the regulation was invalid on various administrative and constitutional grounds. The court denied the challenge, finding that the regulations were a valid exercise of government authority as part of an overall strategy to reduce greenhouse gas emissions. After hearing Syncrude's appeal, the appellate court characterized its key argument as follows: Syncrude was asking the Court to substitute its view for that of the [government] as to whether the [renewable fuel requirement]s could, in the language of [Canadian Environmental Policy Act] subsection 140(2), "make a significant contribution to the prevention of, or reduction in, air pollution." The Court of Appeal rejected this argument, concluding not only that the government's premise is warranted but furthermore that, "[e]ven if there was a solid evidentiary foundation establishing a different scientific opinion . . . it would not detract from the [government] forming a different opinion on admittedly different evidence."