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bserving
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redicting
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C
limate
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onditions
the review revealed that, of the 866 peer-reviewed papers considered,
most impact studies were based in North America, northern Europe and
Russia. There were very few studies on impacts in South America, and
even fewer from Africa (mostly South Africa) and Asia (mostly Japan).
Other uncertainties with regards to the impacts of climate change
on biodiversity can be drawn from the impacts of interactions between
climate change and other drivers of global environmental change in
ecosystems. Indeed, models often separate the impacts of climate change
from other human activities. For example, human land and water use
patterns are available for many parts of the world, but are not widely inte-
grated into the typical models used for looking at biodiversity impacts.
15
Moreover, ecosystems are complex, and therefore responses to climate
change are rarely linear. Changes may take place in the form of sudden
shifts, whose timing and location are difficult to predict. Such responses
may include thresholds beyond which adaptation may be impossible.
16
This uncertainty is exacerbated by the fact that downscaling of climate
data is particularly poor for precipitation and extreme events.
However, despite uncertainties, conserving biodiversity can be an
important safeguard. Diverse ecosystems may to some extent buffer
against moderate changes in climate. In particular, the diversity of species
and interactions amongst them, as well as landscape-scale habitat hetero-
geneity, may provide a range of natural adaptive capacity in the face of a
certain level of change.
17
Partnerships and alliances
To improve information sharing and collaboration between the climate
and biodiversity communities, strategic partnerships and alliances are
crucial. A great amount of knowledge in both fields currently exists, but
there is often little communication and sharing of data and
information. Furthermore, while current projections of
climate change impacts are based on both observational data
and modelling, there is a need to ensure further collabora-
tion between scientists generating each type of data. Climate
change is a multifaceted issue and therefore addressing it
requires a multidisciplinary and multilevel approach.
Convention on Biological Diversity (CBD) contributes
to relevant processes under the World Meteorological
Organization (WMO) and benefits enormously from the
contribution of WMO to the development of scientific
information on climate and climate change. With regards to
World Climate Conference-3, this collaboration will allow
the climate community to providemore user-oriented infor-
mation and predictions, andwill in turn improve access and
use by CBD of climate information and prediction.
In addition, the secretariats of the CBD and UNFCCC
collaborate on a number of issues ranging from the provision
of inputs and views, to participation in respective processes,
to ensure that activities are mutually supportive. The work
by the secretariats is also supported by a number of official
processes such as AHTEG, convened under the CBD. In fact
this AHTEG has issued an action pledge under the Nairobi
work programme on impacts, vulnerability and adaptation
to climate change on improving bioclimatic modelling.
When running models, the availability of data is often
a limiting factor. The Global Biodiversity Information
Facility (GBIF) and the CBD secretariat signed a
Memorandum of Cooperation in July 2003. The goals of
this agreement include facilitating the development and
implementation of technologies and best practices that will
be necessary to access, share and disseminate biodiver-
sity data via the Internet. On the issue of climate change,
GBIF is contributing to the construction of the Global
Earth Observation System of Systems (GEOSS) in order
to link biodiversity data with climate data. GEOSS links
together existing and planned observing systems around
the world, combining the thousands of different instru-
ments into coherent data sets.
18
Conclusion
Despite their limitations, bioclimatic models allow a useful
and often accurate first assessment of changes in biodiver-
sity, especiallywhen informed by observational data. Policies
must be formulated taking into account the likely impacts
from a range of climate change scenarios and projections.
Although uncertainty in models is unavoidable given
the complexity of climate-biodiversity interactions and the
impacts of other drivers of change, this uncertainty should
not become a reason for inaction. Perhaps biodiversity and
climate change policy should best be considered as risk
avoidance and minimization in order to balance the prob-
ability of certain events with the costs of addressing them.
As both the climate and the natural environment are
highly complex systems, the exact replication of their func-
tioningwill never be achieved, despite advances inmodelling
techniques. Therefore, one must make the best use possible
of existing knowledge and techniques, which is made possi-
ble through effective collaboration and partnerships.
Red-eyed Tree Frog,
Agalychnis callidryas
, Gandoca Costa Rica. Since frogs
rely on water to breed, any reduction or change in rainfall could reduce frog
reproduction. Moreover, rising temperatures are closely linked to outbreaks
of a fungal disease that contributes to the decline of amphibian populations,
especially frogs in Latin America
Image: Sonia Gautreau