Lecture Changing perspectives on the environment

Lecture 2. Changing perspectives on the environment

Over the past five decades, we have become increasingly aware of environmental problems at the local, national, and global levels. During this period, many natural resource and environmental issues have grown in scope and urgency. In 1970, the Environmental Protection Agency was created in the United States to respond to what was at that time a relatively new public concern with air and water pollution. In 1972, the first international conference on the environment, the United Nations Conference on the Human Environment, met in Stockholm. Since then, growing worldwide attention has been devoted to environmental issues.

In 1992 the United Nations Conference on Environment and Development (UNCED) met in Rio de Janeiro, Brazil, to focus on major global issues, including depletion of the earth’s protective ozone layer, destruction of tropical and old-growth forests and wetlands, species extinction, and the steady buildup of carbon dioxide and other “greenhouse” gases causing global warming and climate change. Twenty years later, at the United Nations Rio + 20 Conference on Sustainable Development, countries of the world reaffirmed their commitment to integrating environment and development but acknowledged limited progress toward these goals.1 In 2012, the United Nations Environment Programme (UNEP) report Global Environmental Outlook 5 found that “burgeoning populations and growing economies are pushing ecosystems to destabilizing limits.” According to the report:

[The twentieth century] was characterized by exceptional growth both in the human population and in the size of the global economy, with the population quadrupling to 7 billion [in 2011] and global economic output increasing about 20-fold. This expansion has been accompanied by fundamental changes in the scale, intensity, and character of society’s relationship with the natural world.... Drivers of environmental change are growing, evolving, and combining at such an accelerating pace, at such a large scale and with such widespread reach, that they are exerting unprecedented pressure on the environment.

With the exception of ozone depletion, an area in which major reductions in emissions have been achieved by international agreement, the UNEP report offers evidence that the global environmental problems identified at UNCED in 1992 in the areas of atmosphere, land, water, biodiversity, chemicals, and wastes have continued or worsened. Other UNEP Global Environmental Outlook reports have identified nitrogen pollution in freshwater and oceans, exposure to toxic chemicals and hazardous wastes, forest and freshwater ecosystem damage, water contamination and declining groundwater supplies, urban air pollution and wastes, and overexploitation of major ocean fisheries as major global issues.

Climate change has emerged as perhaps the greatest environmental threat of our time. The 2014 report by the United Nations’ Intergovernmental Panel on Climate Change concludes that:

continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.

In December 2015, a United Nations conference held in Paris resulted in a 195-country agreement to limit and eventually reduce the greenhouse gas emissions that cause climate change. Also in 2015, the United Nations adopted the Sustainable Development Goals including combating climate change and environmental degradation.