About UNEP UNEP Offices News Centre Publications Events Awards Milestones UNEP Store
GEO-3: GLOBAL ENVIRONMENT OUTLOOK  
UNEP Website GEO Home Page

Ecosystems under pressure

Extent of built-up areas (% of total land area)

Population growth and urbanization are drivers of expanding land use for human settlements. Asia and the Pacific, Africa and West Asia see big increases to 2032, irrespective of scenario.

Source: PoleStar (see technical annex)

Key to charts

Biodiversity preservation represents another major environmental challenge at the global level. Without strenuous policy action, humans continue to develop more of the planet, reducing and fragmenting natural ecosystems. The built-up area increases in nearly all regions and scenarios, the only exceptions being North America and Europe where the area declines slightly in Sustainability First (see chart on the right).

Lack of effective controls, including realistic price hurdles to urban land expansion, is most evident in the Security First scenario. The percentage of built-up land may seem small, but the infrastructure network (roads, power lines, airports, harbours and dams) that supports these sites affects much larger areas and also sees dramatic expansion over the next 30 years (see chart above and maps). The introduction of such infrastructure can lead to uncontrolled resource exploitation often linked to hunting and poaching, deforestation, land and water degradation, growing of illegal crops, tourism and land conflicts. In both Markets First and Security First, these resource-driven processes accelerate, with rapid losses of remaining wilderness areas and severe impacts on biodiversity and indigenous peoples. A Policy First world continues to protect additional areas and introduce mitigation measures. It does so, however, at rates far below that of development, as in the previous century. Even under Sustainability First conditions, increasing impacts from infrastructure - the modern world's central nervous system - as well as continued growth in human consumption of fuels, minerals and goods and services from natural resources, cannot be completely avoided. However, levels may stabilize across the 30-year period.

Together with the growing impacts of climate change, these developments severely deplete biodiversity in most regions in all scenarios (see maps). One particularly troublesome result related to climate change is that significant areas are at risk because the natural vegetation cannot adapt to the rates of change in temperature and precipitation.

Some change for the worse appears unavoidable in almost any scenario that can be considered for the next 30 years. Nevertheless, reductions in the emission of greenhouse gases, coupled with bold conservation initiatives, including the following, can have a significant limiting effect on the impacts:

  • a sharp reduction in further expansion of infrastructure into remaining wilderness areas;
  • curbs on further fragmentation of already impacted areas;
  • implementation of mitigation measures to reduce impacts on biodiversity from existing networks;
  • introduction of potentially costly restoration measures; and
  • demarcation of wide buffer areas around nature reserves.

Pressures also increase on coastal ecosystems in most regions and scenarios. In addition to pressures from the direct exploitation of resources in these areas, there are also impacts from coastal infrastructure and land-based sources of pollution (see chart below). These pressures are especially large in Asia and the Pacific, where they stem from various sources, dominated by agricultural activity. West Asia also faces rising pressures under Security First and Markets First conditions, but generally sound water management practices in the region have a very positive effect, especially in Sustainability First.

Potential increase in nitrogen loading on coastal ecosystems
  North America Latin America and the Caribbean Africa Europe and Central Asia (without Turkey) West Asia (with Iran and Turkey) Asia and the Pacific (without Iran)
Markets First
Policy First
Security First
Sustainability First
Expected increase by 2032     small     large     very large

Nitrogen loading can be taken as a proxy for a wider range of land-based pollution on coastal ecosystems. Currently it is especially large in East Asia, and Western and Central Europe and along the Mediterranean coast of West Asia and Northern Africa.

Source: IMAGE 2.2 (see technical annex)

In Europe the Mediterranean coast comes under special pressure through a combination of urban growth with inadequate waste water treatment facilities, tourism and intensively farmed croplands close to major river mouths. Latin America and the Caribbean currently features minor pressure from land-based sources of pollution along much of its coastline, compared to other regions, but this rises sharply over the coming years. North America and Africa also start from a relatively low base, but certain areas, such as the mouths of large river systems like the Mississippi and the Nile are of key concern.

Land area impacted by infrastructure (% of total land area)

Human demands for resources and transportation continue to impact on biodiversity and ecosystem function up to 2032.

Source: GLOBIO (see technical annex)