Legacy effects are the impacts that one generation leave on the environment for future generations to inherit. There are very few parts of the globe where human beings have not left their imprint or legacy. Archeological evidence suggests that from the earliest times the human, the hunter, was responsible for the extermination of numerous other forms of life—flora and fauna—a pattern that persists today. The early civilizations changed water-courses, initiated farming, and denuded landscapes of many species of trees and shrubs; the barren lands of the eastern Mediterranean, for example, are largely a legacy of the classical period of ancient Greece. The advent of industrialization and mass production has resulted not only in further damage to the natural landscape as massive resource depletions take place, but also legacies of unsightly built environments.
Legacy effects are not all negative, at least in terms of public perception. Although the classical period saw the destruction of woodlands, it did leave a legacy of fine buildings that are seen by most as environmental attributes. The dividing line between what is a negative legacy effect on the environment and what is not is sometimes a fine one to draw and depends on who is being consulted.
Legacy effects occur because of the lack of a full allocation of long-term property rights to resources, which leads to excessive myopia in decision making. The 1987 report of the World Commission on Environment and Development, Our Common Future (the Brundtland Report), emphasizes that sustainable development requires current generations to leave an adequate legacy of resources for future generations. To achieve this goal, individuals have to take responsibility for resources. Without a complete legal definition of who owns these resources, however, it is difficult to ensure that adequate conservation is achieved. If this is not accomplished, then what is known as the “tragedy of the commons” becomes apparent as individuals in each generation excessively exploit resources with no regard to future needs or the implications for future generations.
Dealing with legacy effects poses a variety of public policy challenges. Ideally, property rights should be allocated across generations so that decisions regarding current consumption are made with due cognizance of their implications for future generations. Because the lack of adequate property-rights allocations in the past has burdened current generations with environmental costs, an inevitable degree of remedial action may be justified. In many countries, for example, large sums are being spent on cleaning watercourses where runoff from mining activities prevents plants or fish from living, on removing dams to allow salmon to move upstream, and on reforestation. The general approach to these legacy situations is to apply some form of informal benefit-cost analysis that seeks to weigh the immediate costs of remediation against the social benefits for future generations. In many cases, the financial burden for such measures is spread across communities as the state directly shoulders the burden, but in other cases there may be requirements for particular groups to pay. It may, for example, be necessary for a land developer to clean contaminated soil associated with a previous land use before new construction is allowed. In some cases, this latter approach can actually pass part of the cost back to those who caused the problem; in the land use example, the seller of the contaminated site will get a lower price for it.
The embrace of legacy effects in the public policy process often encounters an informational problem. Technology changes over time, and the long-term environmental implications of any action are difficult to fully assess, particularly when there are major technological or social changes taking place. In general, the world’s current generations are materially better off than previous generations; its members live longer and there is also evidence that in many respects the environment is locally less polluted than it was forty or fifty years ago. Consequently, simply thinking in terms of the costs of future remedial actions to counter ongoing environmental intrusions may produce overestimates. Additionally, there are some current actions now that we do not understand well enough to be able to assess their legacy effects, either negative or positive. The lack of any real indication of the risks involved makes “insurance” policies difficult to formulate in these circumstances, and hence many advocate abstinence from any actions without knowing their full implications.
To combat current environmental effects that we know will be passed on to future generations, a number of micro- and macrostrategies have been adopted. At the micro level, many countries seek to economize on excessive resource depletion by stimulating recycling—for example, by requiring payment of a deposit at the time of purchase of an item, which is refunded when the item is returned for recycling. These initiatives encompass such items as bottles and cans, and even motor vehicles in some Scandinavian countries. There are also various standards that effectively “sunset” any adverse environmental effects—for example, the compulsory use of biodegradable materials for some products, or term limits on fisheries.
Macro legacy effects include global warming and the handling of nuclear products. Both of these are long-term matters affecting generations extending far into the future. They also have international ramifications; the effects represent a legacy with implications for citizens of other countries. Efforts to deal with this type of intergenerational externality have involved the United Nations (e.g., the International Atomic Energy Agency) and a series of global summits (resulting in, for example, the Kyoto Protocol).
SEE ALSO Natural Resources, Nonrenewable; Pollution; Tragedy of the Commons
Button, Kenneth J., Roger Stough, Peter Arena, et al. 1999. Dealing with Environmental Legacy Effects: The Economic and Social Benefits of Acid Mine Drainage Remediation. International Journal of Environment and Pollution 12 (4) 459–475.
World Commission on Environment and Development. 1987. Our Common Future. Oxford: Oxford University Press.