Deforestation and water stress
The risk of land degradation is linked to forest cover. A complex set of forces determines the future of forests in the region. Population growth, including urban expansion in all scenarios and economic improvements in all but a Security First situation, lead to mounting demand for agricultural land at the expense of forest area. Efforts to address the problems of mega-cities in the worlds of Policy First and Sustainability First also increase deforestation as settlement programmes encourage wider dispersal. In a Security First world there are added pressures as the poor are pushed onto ever more marginal lands.
These pressures are cushioned to some degree by advances in agricultural technology but the effects differ across scenarios. Advances may be most rapid in Markets First, but probably do not have environmental protection as their key goal. More importantly, economic forces such as rising prices for timber and non-timber forest products, which can encourage both deforestation and reforestation, are balanced against reductions in subsidies that have driven conversion of forest and woodlands to agriculture, and other economic instruments introduced to improve conservation. These all influence the area and condition of remaining forests. Market instruments play the biggest role in a world of Markets First. These are complemented in the worlds of Policy First and Sustainability First by government and local programmes to subsidize reforestation and encourage a shift to agroforestry, and by direct efforts to preserve biodiversity.
The net result is that the total area of forest in Asia and the Pacific declines over this period, but this effect differs significantly across sub-regions and scenarios. South and Southeast Asia suffer the most significant losses in total forest area. Whereas Northwest Pacific and East Asia experience a net increase in forest area due to plantations, the total area of undisturbed natural forest declines. In Australia and New Zealand and the South Pacific, the effect of replanting is such that more new forest is created than is used for logging or other production.
Water stress is presently one of the most contentious problems in Asia and the Pacific, leaving aside the small Pacific Island Countries (PICs), and it remains high on the agenda for the foreseeable future (see on the right). Growth in demand is especially high in a Markets First world, but also in Policy First and Sustainability First, where economic growth is similarly robust. Water pricing and more efficient use of water in agriculture due to advances in biotechnology help to temper this growth. Under the Markets First scenario, water withdrawals increase in all sectors, especially when further expansion of irrigated area is assumed. These increases in water withdrawals lead to an expansion of areas with severe water stress in South and Southeast Asia in all scenarios and more people are affected throughout the region. In Security First overall growth in demand is moderated by slower economic growth in many sub-regions and no further expansion in irrigated areas, rather than any significant efforts to become more efficient.
Under the Policy First and Sustainability First scenarios, where effective policies and lifestyle changes combine with greater regional cooperation and technology transfer, water withdrawals remain at current levels or even decrease in most of the rest of Asia. However, with population growth continuing, the number of people living in areas under severe water stress continues to increase across Asia.
Urban areas, especially the growing mega-cities in South, Southeast and
East Asia, face many trials in addition to water stress. They include
land use pressures, air and water pollution and solid waste overload.
All these challenges are related to rapidly growing populations, from
both natural growth and rural-urban migration, and increasing economic
activity. Trends in local and regional air pollution depend heavily on
choices in energy production. If coal continues to dominate, as is likely
in a Security First situation with reduced trade or in a world
of Markets First where the cost is what counts, then local air
pollution tends to worsen significantly.
The increase is most evident in Security First, where little effort is made to control sulphur emissions from stationary sources and nitrogen oxide emissions from stationary and mobile sources (see charts above). The setting and enforcement of regulations prescribing cleaner fuels and fuel uses, cleaner technology and upgraded emission standards, all help to curb these trends in a Policy First world. In Sustainability First, major efforts towards decentralization with dispersed satellite cities relieve the pressures. This step, combined with better physical planning and management of urban systems, leads to more effective coordination of growth, distribution of clean industry, servicing, handling of pollution streams and housing design.
These policies help to buffer ill-effects in the Policy First and Sustainability First scenarios, but the higher levels of economic growth make environmental protection difficult. In all scenarios, the amount of built-over land grows significantly across the region (see chart on the right).
Similarly, CO2 emissions and production of solid waste (see above) increase in most scenarios. Emission standards, which tend to be weak or lacking in a Security First situation, help to limit the growth in air pollutants in the other scenarios, especially in Policy First. Emissions of CO2 increase more rapidly in Markets First circumstances because of high economic growth. In Policy First, advanced technologies are introduced to reduce CO2 emissions. Because a Sustainability First society shifts from conventional to sustainable lifestyles, CO2 emissions are somewhat mitigated. On the other hand a Security First society holds on to technologies with low energy efficiency. CO2 emissions increase most rapidly in this scenario everywhere except in Central Asia where low economic activities mitigate CO2 emissions vis-à-vis Markets First. The effects of lifestyle changes are also evident in the lower levels of solid waste production in Sustainability First.