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.

In a recent article reviewing the U.S. Supreme Court's environmental decisions over the last 30 years (1969-1999), Professor Richard Lazarus argues that "the Justices have never fully appreciated environmental law as a distinct area of law."¹

A recent headline on the front page of the Wall Street Journal hailed the opening of the nation's first "butterfly bank." The "deposits" in this unusual bank are conservation credits earned by preserving an important area of habitat for the Quino checkerspot butterfly, an endangered species restricted to California. The bank's intended customers are other landowners who hope to develop other sites where the butterfly occurs. In order to do so, they can buy credits from the private entrepreneur who established the butterfly bank.

The 1999 National Nuclear Security Administration Act (NNSA Act) threatens to reverse 20 years of reforms and court decisions intended to bring the U.S. Department of Energy (DOE) into compliance with environmental laws and regulations. The NNSA Act, enacted in the wake of allegations of spying at Los Alamos nuclear weapons laboratory in New Mexico, established a semi-autonomous agency within DOE—the National Nuclear Security Administration (NNSA). The NNSA operates nine laboratories and facilities within the U.S. nuclear weapons complex.

Editors' Summary: Although the Clean Air Act is the primary tool used for controlling air toxics, the dramatic increase in toxic tort cases brought under common-law theories such as nuisance, trespass, negligence, and strict liability for ultrahazardous activities has raised concern in the industrial community that compliance with regulatory requirements may not protect industry from large-scale toxic tort liability. This Article analyzes the implications of common-law liability on the selection of air quality controls.

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.

In Environmental Federalism Part 1: The History of Overfiling Under RCRA, the CWA, and the CAA Prior to Harmon, Smithfield, and CLEAN, the history of judicial and administrative decisions relating to overfiling under the Resource Conservation and Recovery Act (RCRA), the Clean Water Act (CWA), and the Clean Air Act (CAA) was analyzed. The history showed that the U.S. Environmental Protection Agency (EPA), with limited exceptions, generally was understood to have overfiling authority under RCRA, the CWA, and the CAA. The limited exceptions focused on two situations.

In the span of just a few years, the U.S. Supreme Court has brought the venerable constitutional concept of federalism back to life with a vengeance. In the 1999 Term alone, the Rehnquist Court struck down three federal laws for violating basic principles of federalism and narrowly construed a fourth to avoid any conflict with those precepts.

Editors' Summary: In recent years, vindication of private-property rights has been the rallying cry of various citizen groups and politicians who believe that certain regulatory restrictions—especially environmental protection measures—have "gone too far" and that the Fifth Amendment is an insufficient safeguard of private-property rights.

On June 29, 2001, the last day of the October 2000 term, the U.S. Supreme Court granted certiorari to consider "whether the [Ninth Circuit] Court of Appeals properly determined that a temporary moratorium on land development does not constitute a taking of property requiring compensation under the Takings Clause of the [U.S.] Constitution?" The case, Tahoe-Sierra Preservation Council, Inc. v. Tahoe Regional Planning Agency, provides the Court with an opportunity to clarify its opinions in First English Evangelical Lutheran Church of Glendale v.