Document Summary
Published:
1 Mar 2013
Climate change and water resources in the tropical Andes
Paper discussing climate change impacts on water resources in the tropical Andes
Produced by the Inter-American Development Bank, this paper focuses on the effects of climate change on water resources in the tropical Andes. It begins by looking at recent trends in temperature and precipitation and the various attempts to extrapolate into the future, based on different Intergovernmental Panel on Climate Change (IPCC) scenarios. It then discusses how climate change is likely to impact natural systems and the services they provide, the social and economic tensions of increased water stress, and the challenges that lie ahead.
The tropical Andes is a region of great topographical variation, making accurate climate modelling particularly difficult. Further complications arise due to significant year-to-year variations in precipitation caused by the El Niño-Southern Oscillation, which can cause both torrential rains over coastal desserts as well as widespread drought. Several studies have concluded that the region has increased in temperature by around 0.7 degrees Celsius between 1939 and 2006, but a lack of historical data and the modulation caused by the region’s topography make predicting precipitation more difficult. It is thought that the likelihood of extremely hot years will increase, that the highest elevations will experience the most warming, and that wet-seasons will migrate and intensify.
Glaciers are at particular risk; Venezuela has lost 95 per cent of its glacier surface area since 1850, while Columbia lost eight of its 14 glaciers during the last century, which is a pattern repeated across the region. Impacts will include a disruption to glacier hydrology downstream; as glaciers disappear, wet-season flow will increase whilst dry-season flow decreases, thereby increasing water-stress. Also at risk from climate change are wetlands of Venezuela and Peru (increased evapotranspiration, soil erosion, sedimentation, etc.), a major water source for many of the largest cities in the region (a demand that will continue to increase).
As demand and water-stress grows, so too do tensions such as those which see local peasants set against mining companies and water-intensive industries (often favoured by institutional arrangements primarily concerned with states’ economic interests). Agriculture and livelihoods will be impacted, signalling a further increase in urbanisation. The paper concludes that in order to prepare for these impacts, a variety of measures must be undertaken, including more education, knowledge and technical transfers, participatory adaptation and a strengthening of institutional capacity.
The tropical Andes is a region of great topographical variation, making accurate climate modelling particularly difficult. Further complications arise due to significant year-to-year variations in precipitation caused by the El Niño-Southern Oscillation, which can cause both torrential rains over coastal desserts as well as widespread drought. Several studies have concluded that the region has increased in temperature by around 0.7 degrees Celsius between 1939 and 2006, but a lack of historical data and the modulation caused by the region’s topography make predicting precipitation more difficult. It is thought that the likelihood of extremely hot years will increase, that the highest elevations will experience the most warming, and that wet-seasons will migrate and intensify.
Glaciers are at particular risk; Venezuela has lost 95 per cent of its glacier surface area since 1850, while Columbia lost eight of its 14 glaciers during the last century, which is a pattern repeated across the region. Impacts will include a disruption to glacier hydrology downstream; as glaciers disappear, wet-season flow will increase whilst dry-season flow decreases, thereby increasing water-stress. Also at risk from climate change are wetlands of Venezuela and Peru (increased evapotranspiration, soil erosion, sedimentation, etc.), a major water source for many of the largest cities in the region (a demand that will continue to increase).
As demand and water-stress grows, so too do tensions such as those which see local peasants set against mining companies and water-intensive industries (often favoured by institutional arrangements primarily concerned with states’ economic interests). Agriculture and livelihoods will be impacted, signalling a further increase in urbanisation. The paper concludes that in order to prepare for these impacts, a variety of measures must be undertaken, including more education, knowledge and technical transfers, participatory adaptation and a strengthening of institutional capacity.
