Climate change in the UKOTs an overview of the ... - JNCC - Defra

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Box 6. Three temperature increase scenarios
It is a foregone conclusion that the Earth’s temperature will continue to rise for some
time to come. What is not known is the extent of the change that will take place. Climate
scientists have modeled different scenarios of mean temperature changes with a view to
predicting what some of the likely impacts of temperature changes would be.
Global mean temperature changes of up to 1.5°C would exacerbate current key vulnerabilities
and cause others, such as negative health effects caused by heat waves, floods an
droughts, as well as malnutrition and infectious diseases, millions more people exposed to
increased water stress, increased damage from storms and floods, increased coral bleaching.
Global mean temperature changes of 1.5°C to 3.5°C would result in an increasing number
of key impacts at all scales, such as many million more people at risk from coastal
flooding, widespread loss of biodiversity, and commitment to widespread melting of the
Greenland and West Antarctic ice sheets with associated sea level rise.
Global mean temperature changes greater than 3.5°C would exceed the capacity of all
systems - physical, biological and social, in particular of human societies - to adapt to this
extent of warming, especially since it can be even more pronounced regionally. As examples,
about 30% loss of global coastal wetlands and widespread mortality of corals.
Need for action in the UKOTs
Based on the data and information that are
available (some of which is summarised
below), climate change is already affecting
UKOTs. The IPCC projects that, even in the
best possible scenario, the effects of climate
change will worsen before the situation
improves. UKOTs have no control over
the storm surges that affect their shores,
nor can they regulate the increasing ocean
temperatures that affect their coral reefs or
fish and marine animals in their waters, but
what they can do is plan for these threats
and put in place systems and infrastructure
to reduce risk and build resilience.
UKOTs cannot afford to adopt a wait and
see attitude. The economies of the territories
are too small and they are too
dependent on sensitive ecosystems. If
they are completely unprepared, the
external shocks of some climate change
impacts could be devastating. In the most
extreme circumstances, some UKOTs
Source: German Federal Ministry for the Environment, Nature Conservation
and Nuclear Safety et al., 2007
could lose land because of rising sea
levels. Even without the most extreme scenario
becoming reality, what’s at stake for
most territories is a way of life and many of
the natural and cultural features that are so
much a part of their identity.
Vulnerability to climate change can
be intensified by the presence of
other stresses
Climate change is not the only threat that
UKOTs face. Each territory has its particular
mix of stresses on the natural and
physical environments. Some of these
pressures are a result of changes people
have made to the landscape and oceans.
Some are a consequence of pollution, the
introduction of invasive alien species,
and the over harvesting of plants, fish and
animals. Some have their roots in natural
phenomena. Nevertheless, whatever the
source, together with climate change, they
increase risk and reduce resilience to natural
hazards in a mutually reinforcing