Environmental Engineering Reference
In-Depth Information
Climate change and its impact
D. Nogues-Bravo, J.I. Lopez-Moreno and S.M. Vicente-Serrano
9.1 Introduction
We are currently experiencing a period of global climatic changes that are affect-
ing the biosphere and the ecosystem services that sustain our societies. The re-
lationships and feedbacks between the different abiotic and biotic elements that
compound the Earth's global ecosystem, such as climate, oceans, glaciers and
rivers, biodiversity and human societies, are usually complex and non-linear. In
any case, climate and climate changes through time are clearly the engine that
modifies our environment - its fingerprints present all over the world (Parmesan
and Yohe, 2003; Root et al., 2003) - and mountains are no exception to this rule.
Mountains are amongst the most fragile environments in the world (Diaz et al.,
2003). They are a repository of biodiversity, water and other ecosystem services
(Korner, 2004; Viviroli and Weingartner, 2004; Woodwell, 2004), and their influ-
ence exceeds their geographical limits and extends to the surrounding lowlands.
Approximately 26% of the world's human population inhabit mountainous regions
(Meybeck et al., 2001). Mountains constitute centres of endemism for biodiver-
sity, harbouring endangered species and habitats. Mountains also provide services
with tangible economic value, such as power supplies, tourism, crop and live-
stock production, and perhaps the most important among them, water, since moun-
tains are the source of approximately 70% of fresh water in the world (Viviroli
et al., 2007).
Climate change could greatly affect these ecosystem services in the coming
decades. However, climatic changes and their influence on the environment are not
confined to recent times. On the contrary, the Earth's global climatic system has
been changing continuously for billions of years and the magnitude and impacts of
such change on mountain ranges have been explored and documented intensively.
This short digression to past climatic changes allows us to place current climate
change and its impacts in a proper context, avoiding on the one hand dramatic
interpretations but, on the other hand, recognizing the ability of climatic changes
to radically transform physical, biological and social realms. Projections of future
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