As lawmakers debate the best way to confront the issue of global warming, it is becoming clearer that the issue may be one of this generation's most important policy decisions. Despite increasing public awareness of the perceived problem, the federal government successfully circumvented the issue for most of this decade, thereby creating a regulatory void that environmentalists and scientists have sought to address.

To fill the vacuum, California developed a regulatory response to the mounting data suggesting a man-made cause for climate change. While the state should be admired for its initiative, these regulations will have a significant impact on California's transportation industry. The first, an Airborne Toxic Control Measure for In-Use Diesel-Fueled Transport Refrigeration Units and Transport Refrigeration Unit Generator Sets (TRU ATCM) attempts to regulate emissions from refrigeration units affixed to highway semi-trailers that transport perishable goods. The second regulatory program, authorized by the California Global Warming Solutions Act of 2006, seeks to reduce greenhouse gas (GHG) emissions by improving heavy-duty vehicles' fuel economy through the use of aerodynamic devices.

This Article will examine California's attempt to address the global warming issue through the use of the aforementioned programs by explaining the programs themselves and their practical impact on the transportation industry, and analyzing the likelihood of the regulations surviving legal challenge. The result will demonstrate that due to the unique and fluid properties of the contaminants that are being regulated, U.S. courts will need to reexamine their current analysis of such regulations and develop a new standard for reviewing GHG emission regulations. Such an approach is likely to result in a more equitable apportionment of the burdens associated with realizing the global benefit of GHG emission reductions.