There can be no sustainable development without sustainable transportation. It is an essential component not only because transportation is a prerequisite to development in general but also because transportation, especially our use of motorized vehicles, contributes substantially to a wide range of environmental problems, including energy waste, global warming, degradation of air and water, noise, ecosystem loss and fragmentation, and desecration of the landscape. Our nation's environmental quality will be sustainable only if we pursue transportation in a sustainable way.

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.

If we want to think about changes in local sustainability over the last 10 years, perhaps the best place to start is with Al Gore. In 1992, just before the Rio Earth Summit and before he was to be tapped as a vice presidential candidate, then-Senator Gore published a treatise on the environment called Earth in the Balance.

The Defenders of Wildlife Judicial Accountability Project—undertaken with the assistance of the Vermont Law School Clinic for Environmental Law and Policy—seeks to fill a data void on the environmental record of President George W. Bush and his Administration by analyzing all reported environmental cases in which the Bush Administration has presented legal arguments regarding an existing environmental law, regulation, or policy before federal judges, magistrates, or administrative tribunals.

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.

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.

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.