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Problems with water supply, hydropower, agriculture
and biodiversity all have drastic effects on human
health. Agricultural problems will drive poverty
and food insecurity primarily among people living
in the mountains but also in South America as a
whole. Reduced biodiversity and damaged mountain
ecosystems will also threaten the nutritional
ecosystem services they provide. This includes
wild harvesting of edible and medicinal plants and
firewood as well as fresh water. Damage to fish stocks
and unique Andean ecosystems could also threaten
tourism. One broad implication is contribution to
poverty and its wide-reaching associated ills. When
people’s economic situation is worsened, other
negative effects of climate change are aggravated.
Changes inwater availability, particularly inpoorurban
areas, could cause a significant increase in infectious
diseases and generally limit the lives of millions of
the most vulnerable. Access to improved sources of
water for sanitation in Bolivia was about 61 per cent
of the population in urban areas in 2015 (WHO and
UNICEF, 2015) , but only 28 per cent in rural areas. In
Peru, the numbers are 82 and 53 per cent respectively.
Decreased water flow in the dry season will also have
significant effects on sewage systems and sanitation.
Diarrhoea remains a major killer of children in the
world as well as in South America. El Niño events and
temperature increases have also been associated with
increased frequency of diarrhoea in Peru (Checkley
et al., 2000). The relationship between climate change
and diarrhoea, however, remains unclear.
Warming of the climate also influences the spread
of insects and associated diseases (Thomson, 2014).
Vector-borne diseases have moved upward in elevation
Health
as the climate has become warmer. Malaria, dengue
fever and other diseases will therefore become more
prominent in the mountains. El Niño events and
climate change have been demonstrated to significantly
increase the altitude at which vector-borne diseases
are experienced in Colombia (Poveda et al., 2000).
Increased frequency of extreme El Niño events is
estimated to contribute to an increase of vector-
borne disease (Thomson, 2014). These phenomena in
combination could have a significant effect, especially
in highly populated areas in the mountains, such as
Bogotá andMedellín in Colombia. A recent study from
the Antioquia region in Medellín demonstrates that
malaria will become more prevalent in the highlands
because of increased temperatures (Siraj et al., 2014).
The Andes are characterized by significant risk for
extreme events. Some are climate driven, such as
wildfires, mudslides and avalanches, while others
are not, such as volcanic eruptions and earthquakes.
However, climate change will increase vulnerability
even to non-climate-driven disasters. For example,
the steep slopes of the Andes combined with warming
and increasingly concentrated precipitation in some
places will increase the risks of landslides. These
topographic features exacerbate the problems already
expected from increasingly concentrated rainfall and
increased frequency of extreme El Niño events. This
directly threatens infrastructure, ecosystems and
human lives. Socioeconomic issues determine to a
significant degree the outcome of such disasters for
different social groups. In cities in the Andes, slums
are often found along the steepest hillsides and have
poor building quality (O’Hare and Rivas, 2005).
These areas, home to millions of people, are the most
vulnerable to landslides. Due to lack of legal ownership
for the residents, as well as lack of infrastructure, these
communities have restricted capacity to adapt.
Melting glaciers also contribute to increased risk of
Glacial Lake Outburst Floods (GLOFs). As glaciers
melt, lakes of meltwater build up and can sometimes
burst out, causing severe damage. These lakes are
often particularly fragile because the dam is made
of loose moraine gravel and rock. Climate change
is increasing the risk of GLOFs in the Cordillera
Blanca, both because of increased melting and
through an increased number of extreme events.
In 1970, an earthquake caused the bank of a glacial
lake on the HuascaránMountain to collapse, causing
a flood that killed 20,000 people (Hegglin and
Huggel, 2008). In 1941 a similar disaster occurred
in the same area after a huge part of a glacier fell
into Lake Pallqaqucha, causing a GLOF which
killed over 50,000 inhabitants of the city of Huaraz.
The Peruvian government has made significant
progress in monitoring these lakes and creating risk
reducing infrastructure, such as overflow tunnels.
These demonstrated their worth in 2002 when a
rock avalanche caused a 70 m high wave in Laguna
Safuna. Due to the overflow tunnels, no human lives
were lost, despite significant damage and the death of
a number of grazing animals (Chevallier et al., 2010).
Glacial Lake Outburst Floods in the Tropical Andes