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.

Key to charts

Population living in areas with severe water stress: Asia and the Pacific (%) When more than 40 per cent of the renewable water resources of a river basin are being withdrawn for human use the river basin is considered to be under severe water stress. Nearly 1 700 million of the world's 2 400 million people in areas facing severe water stress live in Asia and numbers are highest in South Asia. Apart from wealthier countries in the region, demand for water rises significantly, with more and more people living in regions suffering from severe water stress. Source: WaterGAP 2.1 (see technical annex)

Number of people living in areas with severe water stress: Asia and the Pacific (million persons) All the pie charts show total region impacts. The top left pie shows the current situation, the relative size of the others reflects the magnitude of impacts by 2032 under the four scenarios. Source: WaterGAP 2.1 (see technical annex)

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.

Key to charts

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.

Energy-related nitrogen oxide emissions: Asia and the Pacific (million tonnes nitrogen) Nitrogen oxide emissions grow rapidly with the increase of motorization and rise even in a Policy First scenario. A very high increase is expected in South Asia in line with the large increase in motor traffic. Source: AIM (see technical annex)

Energy-related sulphur dioxide emissions: Asia and the Pacific (million tonnes sulphur) Sulphur dioxide emissions increase most rapidly in a Security First world because little money is invested to reduce emissions. In the other scenarios, especially in Policy First and Sustainability First, the increase of SO2 emissions is less as steps are taken to avoid severe air pollution. In some sub-regions emissions drop below 2002 levels. Source: AIM (see technical annex)

Energy-related carbon dioxide emissions: Asia and the Pacific (million tonnes carbon) Trends under different scenarios are similar throughout the region and reflect both state of technology and lifestyles. Source: AIM (see technical annex)

Municipal solid waste generation: Asia and the Pacific (index related to value of 1 for base year 1995) Total municipal waste is expected to increase more than 150 per cent by 2032 in South Asia, Southeast Asia and Central Asia in a Markets First scenario. Municipal waste generation is closely linked to income level and size of population. Source: AIM (see technical annex)

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.

Extent of built-up areas: Asia and the Pacific (% of total land area)

Built-up area expands as both population and built environment per head of population grow. The latter value is among the lowest in the world in Asia, but with rising incomes and expanding infrastructure, each person's footprint, as measured in built land, grows over the course of the scenarios. Source: PoleStar (see technical annex)

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.