Originally published in Oklahoma Bar Journal - Volume 83, No.5 - February 11, 2012.

Regardless of strongly held beliefs regarding climate change, the law now recognizes — at least as of this writing — that greenhouse gases (or GHG) are “air pollutants” regulated by the Clean Air Act. Entities potentially subject to greenhouse gas regulation, and their counsel, should become familiar with the scope and applicability of this new regulatory structure to ensure that compliance requirements are properly considered in project scoping, timing and staffing.

The impact of U.S. climate change and GHG policy extends far beyond mere compliance with the requirements triggered by the Environmental Protection Agency’s (EPA) new GHG regulations. The Securities and Exchange Commission has issued guidance instructing publicly held entities regarding proper disclosure of risk factors related to climate change. Municipalities and industry are preparing for impacts expected due to climate change, referenced with the umbrella term “adaptation,” and including measures to mitigate the impact of a rise in sea level and changing weather patterns including severe storms, flooding and prolonged drought. Engineering schools are even developing “adaptation” elements within core engineering curricula. Certainly, lawyers should become more aware of these developments to ensure clients are informed of potential legal issues. This article provides a short summary of these developments for all practitioners.

What are greenhouse gases?

Greenhouse gases are those gaseous substances that absorb and emit radiation (energy from sunlight) within the portion of the sunlight spectrum called the thermal infrared range. Generally the concept is that these gases present in our atmosphere, by absorbing and emitting the energy from sunlight, trap this energy within our atmosphere contributing to changes in our climate that may already be occurring.

Greenhouse gases include many naturally occurring substances such as water vapor, carbon dioxide, methane, nitrous oxide and ozone, which may also be emitted from manmade sources, as well as wholly manmade substances, such as chlorofluorocarbons (Freon) and sulfur hexafluoride (SF6). All greenhouse gases are not created equal. Some greenhouse gases trap a lot more heat than others. The degree to which a greenhouse gas traps heat is called the “global warming potential” or GWP. GWPs are calculated in reference to carbon dioxide, and over time, e.g., 100 years. By definition, carbon dioxide’s GWP is 1, with several others as follows: methane, 25; nitrous oxide, 298; HFC-23, 14,800; sulfur hexafluoride, 22,800. Thus, one ton of carbon dioxide would be expected to result in the same degree of heat trapping potential as 0.08 pounds of sulfur hexafluoride (i.e., 1 /22,800 tons x 2,000 pounds/ton)...

Article authored by McAfee & Taft Attorney: Mary Ellen Ternes.

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