Question 8

What is known about the interactions between projected human-induced changes in climate and other environmental issues (e.g., urban air pollution, regional acid deposition, loss of biological diversity, stratospheric ozone depletion, and desertification and land degradation)? What is known about environmental, social, and economic costs and benefits and implications of these interactions for integrating climate change response strategies in an equitable manner into broad sustainable development strategies at the local, regional, and global scales?

Local, regional, and global environmental issues are inextricably linked and affect sustainable development. Therefore, there are synergistic opportunities to develop more effective response options to these environmental issues that enhance benefits, reduce costs, and more sustainably meet human needs.

Meeting human needs in many instances is causing environmental degradation, which in turn threatens the ability to meet present and future needs. For example, increased agricultural production can be achieved through increased use of nitrogenous fertilizers, irrigation, or the conversion of natural grasslands and forests to croplands. However, these changes can affect the Earth's climate through the release of greenhouse gases, lead to land degradation through erosion and salinization of soils, and contribute to the loss of biodiversity and reduction of carbon sequestration through the conversion and fragmentation of natural ecological systems. Agricultural productivity can in turn be adversely affected by changes in climate, especially in the tropics and subtropics, loss of biodiversity and changes at the genetic and species level, and land degradation through loss of soil fertility. Many of these changes adversely affect food security and disproportionately impact the poor.

The primary factors underlying anthropogenic climate change are similar to those for most environmental and socio-economic issues -- that is, economic growth, broad technological changes, life style patterns, demographic shifts (population size, age structure, and migration), and governance structures. These can give rise to:

• Increased demand for natural resources and energy
• Market imperfections, including subsidies that lead to the inefficient use of resources and act as a barrier to the market penetration of environmentally sound technologies; the lack of recognition of the true value of natural resources; failure to appropriate for the global values of natural resources at the local level; and failure to internalize the costs of environmental degradation into the market price of a resource
• Limited availability and transfer of technology, inefficient use of technologies, and inadequate investment in research and development for the technologies of the future
• Failure to manage adequately the use of natural resources and energy.

The linkages among local, regional, and global environmental issues, and their relationship to meeting human needs, offer opportunities to capture synergies in developing response options and reducing vulnerabilities to climate change, although trade-offs between issues may exist. Multiple environmental and development goals can be achieved by adopting a broad range of technologies, policies, and measures that explicitly recognize the inextricable linkages among environmental problems and human needs. Addressing the need for energy, while reducing local and regional air pollution and global climate change cost-effectively, requires an interdisciplinary assessment of the synergies and trade-offs of meeting energy requirements in the most economically, environmentally, and socially sustainable manner. Greenhouse gas emissions, as well as local and regional pollutants, could be reduced through more efficient use of energy and increasing the share of lower carbon-emitting fossil fuels, advanced fossil-fuel technologies (e.g., highly efficient combined cycle gas turbines, fuel cells, and combined heat and power) and renewable energy technologies (e.g., increased use of environmentally sound biofuels, hydropower, solar, wind- and wave-power). Further, the increase of greenhouse gas concentrations in the atmosphere can be reduced also by enhanced uptake of carbon through, for example, afforestation, reforestation, slowing deforestation, and improved forest, rangeland, wetland, and cropland management, which can have favorable effects on biodiversity, food production, land, and water resources. Reducing vulnerability to climate change can often reduce vulnerability to other environmental stresses and vice versa. In some cases there will be trade-offs. For example, in some implementations, monoculture plantations could decrease local biodiversity.