A recent study from European climate change researchers suggests fruit growers in Central Chile ought to prepare for declining water availability between now and 2100.

The report "Contrasting climate change impact on river flows from high-altitude catchments in the Himalayan and Andes Mountains" compares potential outcomes for the Juncal catchment northeast of the Chilean capital of Santiago and the upper Nepalese region of Langtang.

Using a glacio-hydrological model informed by data from high-altitude observations and the latest climate change scenarios, the authors forecast the Nepalese would likely need to prepare for flooding as a result of glacial melt, while Central Chile may be in for a much drier scenario.

"The authors assessed the impact of climate change on the magnitude and timing of catchment runoffs, and found that although both sites revealed a strong decrease in glacier area, the projected impacts differed widely between the two catchments," a release said.

"The authors found no signs of decrease in future water availability in the Langtang catchment in Nepal, with predictions of increased future runoff, limited changes between seasons, and an increase in extreme events.

"In contrast, the runoff was predicted to decrease in the Juncal catchment in Chile, with major seasonal changes due to climate change."

The report, written by Silvan Ragettli (ETH Zurich), Walter W. Immerzeel (Utrecht University) and Francesca Pellicciotti (Northumbria University), urged Chile to make the necessary adaptations to this impending new reality.

"Our findings point to the necessity of identifying coping strategies to a reduction in water availability in the Central Andes of Chile," the authors said.

"All simulations for the Juncal region indicate a significant decrease in summer runoff until the end of the century, and more than 90% of the runs a decrease in total annual runoff.

Further details

While Langtang's ice melt is set to increase, the authors said total ice melt at Juncal was already "beyond its tipping point" at the beginning of this century.

"This contrasting response to climate warming can be explained by differences in the elevation distribution of the glaciers in the two regions. In Juncal, many glaciers are melting up to the highest elevations already during the reference period," the authors said.

"Increasing melt rates due to higher air temperatures cannot compensate the continuous loss of glacier area."

However, the authors emphasized there was a generally large uncertainty in precipitation projects, in particular for Central Chile where "projected end-of-century precipitation changes vary between −50% and +15% in comparison with the beginning of the century".

Headline photo: Mount Juncal, Wikimedia Commons

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