Global Change and Mountains: Consequences, Responses and Opportunities - Impact of Global Changes on Mountains: Responses and Adaptation - page 95

upward shifts of the vegetation line, and changes in the biodiversity of
alpine lakes and streams. The long-term impacts of these changes are not
only of direct relevance to the high mountains, but they will have serious
implications for downstream regions. Mountain regions have experienced
warming of above-average level in the 20th century (IPCC 2007a,b). The rise
in temperature in mountain regions has affected mountain environments
and ecological processes across the globe. In case of the Himalaya, the
progressive warming at higher altitudes has been three times higher in
comparison to global average (Eriksson et al. 2008, Xu 2008).
Warming projections for the current century indicate that the mountain
systems of the world are expected to be warmer in the 21st century although
the rise in temperatures will be disproportionate and in varying magnitude
depending both on the altitude and latitude of mountains all over the
planet (IPCC 2007a,b). IPCC Special Reports on Emissions Scenarios
(SRES) indicates that the highest temperature rise is expected in high
and medium-latitude mountains, including the high-latitude mountains
of Asia, North America and Europe and mid-latitude mountains of Asia
compared to the mountain ranges of Australia and New Zealand (Rial et
al. 2004, Burkett et al. 2005, Nogués-Bravo et al. 2007, Wookey et al. 2009).
The high-latitude mountains of Asia are expected to experience the greatest
increase in temperature, whereas tropical and mid-latitude mountains in
Africa and South America are expected to be less warm with latitudinal
gradient of temperature change (Nogues-Bravo et al. 2007). Depending on
the different emissions scenario the average temperature in the mountain
regions across the globe has been estimated to rise between 2.1ºC and
3.2ºC by 2055 (Nogues-Bravo et al. 2007), which is 2-3 times higher than
the temperature recorded during the 20th century in different mountain
regions of the Earth (Pepin and Seidel 2005).
Mountain ecosystems are expected to react very sharply to climate
change (IPCC 2007a), with both natural and social systems being infl uenced
all over the world (Beniston 2000, 2003, 2005, 2006). These changes can
be irreversible if they are allowed to go beyond the critical threshold
limits (Beniston 2003). Despite long-term predictions about changes in
climatic conditions are not practically possible, but scenarios can be used
to indicate potential changes (Nogués-Bravo et al. 2007). Climate change
affects all spheres of the planet and as well as almost all components of
the anthroposphere. However, the changes in the cryosphere are most
clearly visible (Borsdorf et al. 2010). The climate change has shown the
most remarkable and signifi cant impact on the glaciers which are retreating
fast since the last century. The trend of glaciers melting is global and rapid
which may lead to the de-glaciation of large parts of many mountain
ranges in the world in the next decades (UNEP WGMS 2002). The Alps
are among the most intensely studied mountains on the planet where an