The clearest trend in the Tropical Andes is the increase in air temperature. The Tropical Andes are expected to experience some of the most drastic change in climate in South America (Urrutia and Vuille, 2009; Hijmans et al., 2005). However, projections of future climate change using different models in the Tropical Andes are highly uncertain, particularly for rainfall. For temperature there is a higher degree of agreement between the different models. This is partly because the topography of the region is too rugged to be captured by low-resolution global models. In addition, there is not a high density of meteorological stations, which would be needed for validating and calibrating climate models. Climate models, therefore, differ more from observations in the Andes than in other parts of South America. This is true for both models on temperature and precipitation projections. While especially in short-term projections internal variability (“noise”) of the modelled processes is often larger than any trends, for longer time scales the signal-to-noise ratio improves and allows for deriving robust trends (in particular for temperature).
From collection: Outlook on climate change adaptation in the Tropical Andes mountains
GRID-Arendal and Cartografare il Presente/Riccardo Pravettoni