Global Change: Prospects for Environmentally Sustainable Futures
The most intractable challenges of our generation will be driven by what may be aptly referred to as the Anthropocene-a new geologic eon in which mankind has emerged as a globally significant agent capable of transforming irreversibly, the face of planet Earth. However, humankind’s debut as the preeminent protagonist of global change-actors analogous in influence to the classic roles played by erosion, volcanism and natural selection is only a recent phenomenon. This dates back several thousand years, but has accelerated greatly in scope and influence over the last several centuries.
The concept of global change refers to transformations in the balance of the Earth system at an unprecedented and accelerating rate. The growing demand for food, fibre, shelter, treasure and water has led to a dramatic alteration of the land surface, from natural cover to cultivated and settled lands. The carbon dioxide liberated from land use change has combined with emissions from the combustion of fossil fuels to change radiant energy balance of the atmosphere, leading to a warming of the Earth’s surface, changes in the distribution and quantity of rainfall, and a rise in the mean sea level.
Agricultural, domestic, industrial and municipal wastes are leading to high nutrient loadings in freshwater and marine water systems, accumulated toxins on land and deteriorating air, soil and water quality. Unregulated exploitation and loss of habitat for wild plants and animals has precipitated rapid declines in biodiversity; at the same time invasive species are increasing their dominance. These changes have implications such as diminishing the range of other goods and services that ecosystems provide and narrowing livelihood options, especially for poor agricultural and pastoral communities.
The challenges of global change are fundamentally different from those that our traditional research institutions and policy processes evolved to address. Early work on the limits to growth, Earth’s carrying capacity, and ecological footprints addressed important issues but generally failed to develop a dynamic, causal understanding of how complex coupled social-ecological systems respond to perturbations. More than a quarter century of serious scientific work on the resilience of ecological systems and the vulnerability of social systems is only beginning to provide a foundation for such understanding. Increasingly we are seeing the deployment of epidemiological approaches in ecological applications, especially in diagnostic surveillance of land degradation over large spatial scales.
Epidemiology is based on the premise that cause is discoverable (through a process of induction using the scientific method) by analyzing the patterns of occurrence of that phenomenon in populations. That is, a cause produces risk, which increases the rate of appearance of cases of a phenomenon among those exposed as compared with those unexposed to the cause. Understanding the cause and the mechanism through which it operates allows the design of interventions for prevention, as well as the testing of the effectiveness of those interventions.
Recent efforts to integrate social and ecological understanding have demonstrated the importance of incorporating multiple stressors, explicit pathways of exposure, the possibility of threshold responses, explicit treatment of scale, and attention to the components of adaptive capacity in frameworks for the analysis of vulnerability and resilience. Integration of social and ecological understanding has also drawn attention to the parallels between climatic and chemical “life-support systems” long discussed by Earth science researchers, the elements of livelihood security (e.g., access to and use of resources) emphasized by development practitioners, and the newer emphasis by ecologists and resource economists on ecosystem services.
The most significant idea to emerge in the eon of the Anthropocene is that of sustainability: a normative concept regarding not merely what is, but also what ought to be the human use of the Earth’s resources. The concern for using our understanding of human impacts on the Earth’s environment to help steer our use of the Earth in sustainable directions can be traced back to early work on conservation of renewable resources. A prerequisite for sustainable management is problem-driven research that utilizes these conceptual threshold-vulnerability-resilience frameworks to illuminate the kinds, rates, and magnitudes of specific disturbances beyond which the ability of society to advance human wellbeing can no longer be sustained.
Sustainable policies must be informed by the incontrovertible fact that humans are inextricably embedded in nature. As every cultivator, herdsman or fisherman knows there are limits on our behaviour and consequences for exceeding these. Although the role of government is to enable the attainment of wellbeing for the citizenry, there are principles which must assume new prominence if the goal of wellbeing is to be attained. Public policy on natural resources must be founded on the precautionary principle; look before you leap. There are nascent albeit fragile signs for the emergence of this principle. The Climate Convention, with the Kyoto Protocol, recognizes the need for responsible action on a global basis. More importantly, Millennium Development Goal 7 affirms our collective commitment to ensure environmental sustainability.
Humanity must view the future as a veritable global common. It is not the domain of any sovereign state or any private commercial interests. There is recognition of the effective limits of sovereignty in the creation of the European Union, the East African Community and the World Trade Organization. Public policy must also relentlessly demand and enforce ethics of responsibility and global accountability. The right to private property, the quest for private profit, and the sovereignty of the state do not justify ecologically destructive behaviour.
Transition to social-ecological systems that are sustainable will require courage and wise stewardship. However, the consequences of inaction are grave and undeniably catastrophic. The unvarnished truth is that our children will live in the future we bequeath them. Edmund Burke argued that the present is but an inheritance from the past that belongs, morally and legally, to the future generations as much as to the present. We have an inimitable and historic opportunity to bestow upon successive generations, a future that is sustainable and just as opposed to one of scarcity, inequity and conflict.