“Let No Man Put Asunder:” The Act of God Defense and Climate Change

Posted on November 2, 2017 by Peter Hsiao

Following the punishing hurricanes in the gulf coast and island regions of the United States, concern immediately turned to the environmental impacts of toxic releases from damaged chemical facilities.  EPA reports that 13 of the 41 Superfund sites in the area were flooded by Hurricane Harvey.  High winds and rain damaged the protective cap at the San Jacinto River Waste Pits, risking the escape of dioxin contaminated sediments, and EPA ordered the responsible companies to take immediate action.  Even without an order, facility owners will often act as quickly as possible to contain any spills and mitigate their impacts. 

But as a matter of law, would there be a basis to defend against the EPA order or claims for response costs by asserting the Act of God defense?  CERCLA and the Oil Pollution Act both provide a complete defense to liability if the party can show that the release of hazardous substances (or petroleum under the OPA) was caused solely by an act of God.  The defense is severely limited by the requirement that a natural disaster must be “unanticipated” and an “exceptional” event.  For example, CERCLA’s legislative history says a major hurricane may be an act of God, but may not qualify as unanticipated or exceptional in an area where hurricanes are common.  Reportedly there are no cases where the defense has been successfully raised.

A superstorm such as Hurricane Harvey may present a more compelling case for this defense.  While hurricanes are expected in the area, an event that unleashed an estimated 19 trillion gallons of water can be considered exceptional and arguably unforeseeable, even with the recent history of other superstorms (e.g., Sandy, Katrina).  Successfully asserting the defense will likely depend upon expert testimony showing the facility implemented enhanced protective measures before the storm, probably true for most major industrial facilities in the affected area, and that exceptional circumstances overwhelmed those measures, which circumstances could not have been anticipated or prevented even by the exercise of due care or foresight.  

Comparing the precautions taken by other similarly situated facilities will also be important to establish the standard of care.  For example, the Texas environmental agencies worked with chemical facilities before the storm to protect hazardous waste containers from damage and flooding, and any facility asserting the defense will likely need to have undertaken similar precautions to have any chance of success.  For a toxic tort case, there is no statutory Act of God defense, but the same types of arguments will be used to show the facility exercised due care and reasonable foresight in taking protective measures. These issues will also be presented in insurance claims and litigation regarding coverage disputes. 

The defense however has an additional requirement, that the Act of God not be the result of human action, such as from greenhouse gas emissions.  While the relationship between climate change and these superstorms may not be known until years of further study, there is preliminary evidence that global warming made the storms worse by increasing ocean temperatures and raising the sea level, intensifying the impacts of its wind speed, rainfall and storm surges. 

So the Act of God defense may become impossible to win for a superstorm if man-made contributions were a factor – but is this meaningful?  The defense has never been successfully asserted in any event.  But if an alternative causation for a superstorm can be proven by a preponderance of the evidence, there is a potential basis for the responsible party under CERCLA or a tort theory to seek contribution or otherwise allocate a proportionate share of liability to others.  And the large number of “other” potential defendants who contributed to global warming will raise difficult issues of justiciablity.  The recent superstorms may produce a test case with the right combination of circumstances to squarely present these issues to a court. 

That is, while not a complete defense, climate change may provide new theories for defendants.  When a door closes, a window may blow open.