In the universe of prime suspects for greenhouse gas (GHG) controls, the transportation and manufacturing sectors at first blush seemingly emerge as relative afterthoughts in the legislative and regulatory agenda. While both sectors each contribute roughly one-third of the nation's GHG emissions, they are most often overshadowed by approaches to climate change controls on the utility sector, which contributes a greater percentage of emissions and which has been front and center in the discussions so far. Even the agriculture sector, which contributes only a sliver's share of emissions compared to transportation and manufacturing, at times attracts more of the debate in assessing impacts and approaches to climate change.

Yet, this relative lack of attention on the surface does not translate into a lack of focus by government regulators or any less impact to these sectors. Because of the significance of the emissions from transportation and manufacturing, and due to the operation of law that inevitably will encompass these sectors into GHG regulations in early 2011, neither sector will be immune in the short or long term from the nation's upcoming suite of GHG controls. While each sector poses unique challenges to regulators and legislators beyond those faced by utilities, the current question is no longer whether these sectors will be regulated, but rather when and how they will be.