Governments are disinclined to consider the possible adverse environmental consequences of policies that offer immediate social benefit or political advantage.
Most issues that will require policy attention in the next century are issues that are currently existing and well known. As time goes on they will become more severe and pose major local and global challenges. If these challenges are not addressed, they will give rise to major environmental crises in the 21st century. As such, they are emerging due to lack of avoiding actions. More effort is also needed to understand the mechanisms through which emerging issues become issues for policy. Social and political processes, science and the trend towards public involvement all have a role to play, at least in some countries.
A list of fundamental global issues that threaten long-term sustainability includes: (a) The use of renewable resources - land, forest, fresh water, coastal areas, fisheries and urban air - is beyond their natural regeneration capacity and therefore is unsustainable; (b) Greenhouse gases are still being emitted at levels higher than the stabilization target internationally agreed under the United Nations Framework Convention on Climate Change; (c) Natural areas and the biodiversity they contain are diminishing due to the expansion of agricultural land and human settlements; (d) The increasing, pervasive use and spread of chemicals to fuel economic development is causing major health risks, environmental contamination, and disposal problems; (e) Global developments in the energy sector are unsustainable; (f) Rapid, unplanned urbanization, particularly in coastal areas, is putting major stress on adjacent ecosystems; and g) The complex and often little understood interactions among global biogeochemical cycles are leading to widespread acidification, climate variability, changes in the hydrological cycles, and the loss of biodiversity, biomass, and bioproductivity.
There are numerous examples from the past. Increased and accelerating emissions of carbon dioxide have led to the climate change issue; the continued intensification of fishing activities has led to the collapse of fisheries in many seas, and the relentless pace of urbanization has creating a series of problems for local authorities in developing and developed countries alike. A classic example of an environmental disaster caused by lack of action is the fate of the Aral Sea. Policy makers were well aware that continued and uncontrolled water abstraction for irrigation would lead to the death of the Aral Sea. They could, however, find no other way of meeting the economic imperatives of the time than through ignoring the problem.