1. The threat of climate change
Climate Change and Biodiversity Conservation
The threat of climate change is
real. Atmospheric scientists agree that without urgent measures
to control carbon dioxide and other greenhouse gas emissions,
the global climate will be rapidly and radically changed. The
consequences will be dire for wildlife and natural ecosystems,
with sealevel rise, increased risk of fire and storm, changed
rainfall patterns, and trends towards warming and aridity all
taking their toll. National Parks and endangered species will
be in the front line of the climate assault, and delicate ecosystems
such as coral reefs, alpine meadows, and temperate rainforests
may undergo damaging and irreversible changes.
WWF's mission is the preservation of biodiversity and natural
ecosystems. Therefore we consider solving the climate change problem
as one of the most critical environmental challenges of the coming
decades. Achievement of a solution that results in reduced emissions
of greenhouse gases will depend on the successful implementation
and strengthening of the new UN climate treaty.
National parks and endangered species will
be in the front line of the climate assault
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Nations that are Parties to the UN Framework
Convention on Climate Change (UNFCCC) are committed to the ultimate
objective of "...stabilization of greenhouse gas concentrations
in the atmosphere at a level that would prevent dangerous anthropogenic
interference with the climate system. Such a level should be achieved
within a time frame sufficient to allow ecosystems to adapt naturally
to climate change...". Current greenhouse gas concentrations
are already likely to pose serious risks to some species and ecosystems.
Carbon dioxide (CO2) concentrations are 25 per cent
above preindustrial levels, and rising, while methane (CH4)
concentrations have doubled since the industrial revolution. Recent
severe storms, droughts, floods, and forest fires, although they
cannot unambiguously be linked to climate change, give an indication
of the impacts that could result from human interference with
the climate system, even at current greenhouse gas concentrations.
Storms and hurricanes may become more frequent,
along with severe droughts and floods
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Climatic changes during the quaternary period
(the last two million years), which was characterized by glacial
ice ages and warmer interglacial periods, caused major alterations
in biomes and ecosystems across Europe and North America. Yet
very few species became extinct during this period, other than
those restricted to islands or mountain ranges, because the populations
of plants and animals were able to migrate according to the changing
climatic conditions. But now the situation is very different for
two reasons. First, the rate of climate change may be unprecedented,
and organisms will not be able to adapt or migrate fast enough.
Second, natural habitats are now patchy and isolated, like islands
in a developed landscape, and plants and animals are often blocked
from successful migration.
Evidence suggests that the climate may have already begun to change.
According to historical temperature records, the 1980s was the
warmest decade on record, and 1994 the third or fourth warmest
year since reliable measurements began in 1850. Examination of
annual growth rings from one of the world's oldest trees in Tasmania
show that the last three decades were the warmest in the region
for 2000 years. Some of the strongest supporting evidence for
the existence of a warming trend during the last 100 years comes
from analyses showing that most of the world's mountain glaciers
are shrinking and that snow cover is decreasing too. In the European
Alps, glaciers are melting twice as fast as they did at the end
of the last ice age. Photographic records from the Venezuelan
Andes show that the present day snowline is 600m higher than it
was in 1885. Further indications of the warming trend come from
research into the underlying cause of the desertification that
has taken a grip in the Sahelian countries of subSaharan
Africa. The Sahel is in the grip of a 25year period of low
rainfall and desiccation at least as severe as anything seen during
the last 1,000 years.
WWF is working on a scientific assessment
of the impacts on wildlife and ecosystems
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