ORIGINAL PAPER Climate change in northern Patagonia: critical decrease in water resources Pessacg Natalia 1 & Flaherty Silvia 2 & Solman Silvina 3 & Pascual Miguel 4 Received: 4 June 2019 /Accepted: 9 January 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020 Abstract The current study presents an assessment of the impact of climate change on water yield, one of the main hydrological ecosystem services, in northern Patagonia. The outputs of regional climate models from the CORDEX Project for South America were used to drive the InVEST water yield model. CORDEX regional climate models project for the far future (2071–2100) an increase in temperature higher than 1.5 °C and a precipitation decrease ranging from - 10 to - 30% for the study area. The projected warmer and dryer climate emerges as a robust signal based on model agreement and on consistent physical drivers of these changes. Moreover, both the projected increase in evapotranspiration and the decrease in precipitation contribute to a strong decrease in water yield of around - 20 to - 40% in the headwaters of northern Patagonian watersheds. Comparison of the results in the two basins reveals that the land cover may be considered a buffer of water yield changes and highlights the key role of protected areas in reducing the vulnerability of water resources to climate change. Keywords Climate change . Water yield impact . Patagonian basins . CORDEX models . InVEST model 1 Introduction The rise in temperature associated with anthropogenic climate change affects water resources by altering precipitation, evapotranspiration, soil moisture, surface runoff patterns, and hydrological cycle. In Patagonia, whereas the increase in temperature (up to 1 °C since 1950) has been large compared to the rest of Argentina (Barros et al. 2014; Boninsegna et al. 2009; Rosenblüth et al. 1997; Villalba et al. 2003; Vincent et al. 2005), there has been no significant changes in precipi- tation for the past 50 years, with the exception of a significant negative trend (around 5% per decade) over the northern Patagonian Andes (Castañeda and González 2008; Masiokas et al. 2008). Climate models project around 10–20% less precipitation over northern Patagonia by the end of the century, being the Andes area the most affected by this projected decrease in precipitation (Barros et al. 2014). In hydrological terms, these projections become even more relevant when considering that the maximum average precipitation occurs in the Andes Mountains, where the headwaters of all Patagonian rivers are. This region is one of the few in the continental areas of Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00704-020-03104-8) contains supplementary material, which is available to authorized users. * Pessacg Natalia pessacg@cenpat-conicet.gob.ar; nataliapessacg@gmail.com Flaherty Silvia silvia.flaherty@gmail.com Solman Silvina solman@cima.fcen.uba.ar Pascual Miguel pascual@cenpat-conicet.gob.ar 1 Instituto Patagónico para el Estudio de los Ecosistemas Continentales (IPEEC-CCT CENPAT CONICET), Puerto Madryn, Argentina 2 Universidad Nacional de la Patagonia San Juan Bosco, Trelew, Argentina 3 Centro de Investigaciones del Mar y la Atmósfera (CIMA/CONICET-UBA), DCAO/FCEN, Buenos Aires, Argentina 4 Instituto Patagónico para el Estudio de los Ecosistemas Continentales (IPEEC-CCT CENPAT CONICET), Puerto Madryn, Argentina Theoretical and Applied Climatology https://doi.org/10.1007/s00704-020-03104-8