Since its promotion in the Brundtland Report, the concept of sustainability has had and continues to have a key role in international environmental law. As would be expected, the concept has been subject to increasing critical scrutiny. Summarise the intentions, strengths, and weaknesses of the concept.
The basic intent of sustainable development, as proposed by the Brundtland report, is to meet the needs of the present without compromising the ability of future generations to meet their own needs. The report stated that sustainable development contains two concepts: the concept of needs, especially those of the world's poor to whom overriding priority should be given; and the recognition of limitations imposed by technology and social organisation on present and future environments. The report further recognised that the concept of sustainable development incorporates the economic and social development goals of all countries. It therefore involves a progressive transformation of the economy and society. This is a fundamental change in the paradigm of repairing or preventing damage to the environment now, to integrating environmental interests with social and economic concerns in the present and the future.
The Brundtland report proposes sustainable development as a means to meet the basic needs of all communities over time and space. This embraces the aspiration of achieving equity for all humanity. The report also recognises the need to manage renewable resources within the limits of their regeneration and natural growth. In the critical case of non-renewable resources, such as fossil fuels, minerals and even land, their continued consumption obviously depletes their availability for future generations. Therefore the rate of consumption, combined with recycling and economy of use, should be calibrated carefully to ensure that the resource is not exhausted before acceptable substitutes are developed and available. Such considerations are not merely a matter of policy but also depend crucially on patterns of individual behaviour and consumption. This aspect of reality the report also recognises in advocating political systems that promote and secure citizen participation in decision-making.
Since the report, the concept of sustainable development has been the focus of a proliferation of analyses and definitions. Regardless of the multiple views, it can claim a key strength. That is that its integration of economic and social considerations with those of the environment is far more likely to be adopted and implemented than a narrow focus on the environment. Policies which more narrowly emphasise the remedy of environmental damage and protection of environmental resources will more likely be subordinated to economic and social development objectives. The Brundtland report also emphasises the then novel concept of intergenerational equity. Promoting the concept of equity and fairness not only between generations but between rich and poor societies in the present is clearly commendable. It is commendable because the global environment by definition is shared. Therefore the cost of sustaining that environment should also be shared but according to the relative degrees of impacts and capacities.
Regarding weaknesses, McCloskey (1999) suggests that the report used the term 'sustainable development' as a label that pasted over loosely assembled ideas that were poorly integrated. For example, in stressing the concern with equity between generations, the report is less clear with respect to equity for and within the present generation. Intergenerational considerations are given more attention than intragenerational needs.
McCloskey further suggests that the report is optimistic in appearing to assume that development is more limited by technology than it is by the natural environment. This objection also relates to the anthropocentric view of the report. It fails to consider the protection or use of natural resources from their viewpoint. Are coral reefs and the abundant life they support worth saving for their own sake, for example?
A crucial part of the debate concerns the distinction between those who believe we can consume resources without anxieties because technological creativities can be relied upon to provide solutions, and those who are less optimistic believing we should be cautious and should emphasise the development and uses of alternative technologies now. However, as McCloskey acknowledges, the report does attempt to consider what is an ongoing debate between those who see planet earth as finite and those who see its human occupation as less constrained because of the infinite ingenuity of human beings.
McCloskey notes that the report conveyed the corollary idea that unsustainable development would, by definition, fail. Hence sustainable development would be the natural and rational course to follow. Conversely, development is a condition of environmental protection. Unfortunately, the idea that unsustainable development must fail and hence will not be the course of action itself fails to recognise timescales. As the 'tragedy of the commons' well demonstrates, an unprofitable course of action in the long run may be profitable in the short term. With respect to the perspective of the future, the short term may be more than a decade obviously. A project that may prove unsustainable in 20-30 years time may not deter an investor now. It was beyond the reach of the Brundtland report to address the question of how to weigh the benefits and costs of decisions with different time-scales.
Regardless of these weaknesses, the Brundtland report was an important contribution to the development of international environmental law. It broke new ground in advancing beyond the narrow environmental interests that would likely not have themselves been sustainable in environmental law and practice. It stepped beyond the narrow single-issue focus and considered environmental issues in the 'whole'. In particular, it made the critical attempt to reconcile the otherwise competing goals of development and the environment. For example, although the Rio Declaration itself contained no definition of sustainable development, it was referred to in several of the principles, covering development, eradication of poverty, consumption patterns and demographics, among others. In this respect, Rio continued the line set out in the Brundtland Report of 1987, Our Common Future, as commissioned by the UN General Assembly.
As a principle of soft law, the concept of sustainable development can claim that it has advanced environmental law at national and international levels.