|
| 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.
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.
|
