Perhaps Congress should throw up its hands and move on to something more manageable than global climate change. Richard Lazarus asserts that the challenges of enacting effective national strategies for mitigating and adapting to changes in the Earth's climate are not just "wicked," but "super wicked," meaning they defy resolution.

Over the past several years, considerable public and private efforts in this country have been directed at reducing the risk of cancer that human exposure to high levels of radon gas poses. These efforts appear to have succeeded in raising public awareness of radon and in increasing testing for radon. For the most part, however, these efforts have been directed toward homeowners and have not addressed the problem of radon in residential rental properties. Yet, in 1989, nearly 34 million homes—over one-third of all housing units in the country—were rental units.

A more substantive precautionary principle of international law is evolving as new treaties articulate new measures of precaution in different contexts. Although there is considerable controversy over how to articulate or define a precautionary "principle" of law, the goal is to ensure that the mere lack of scientific knowledge about risks cannot justify a failure to take appropriate precautions. Where we have sufficient evidence of risk, we often take precautions, despite a lack of certainty about those risks.

The Resource Conservation and Recovery Act (RCRA), the Clean Water Act (CWA), and the Clean Air Act (CAA) represent federal regulatory regimes for protecting the environment. Although each statute initially places administrative responsibility in the hands of the U.S. Environmental Protection Agency (EPA), each encourages states, to varying degrees, to take primary responsibility for implementing the statutory regime.