World Nature Conservation Day: Water resources will become uncertain

In terms of water resources, some regions of the world are highly dependent on snowmelt. However, with anthropogenic climate change, runoff will become much less predictable. Making the management of freshwater resources even more difficult.

Météo France has just announced it. July 2022 will be ” very probably “ the driest month of July since 1959. This seems to be just the beginning. Simulations show a continuous increase in droughts of the ground throughout the XXI^e century as a result of global warming. At least, concerning our country. Because elsewhere, the forecasts are not necessarily the same.

Of the researchers from the National Center for Atmospheric Research (NCAR/Ucar, United States) show, for example, that in regions of the northern hemisphere dominated by snow, it is the lack of predictability of water resources that should dominate. Even in areas that will continue to receive roughly the same amount of precipitationthe debit waterways will become more variable and unpredictable.

“In these regions, water management systems are based on the predictability of snow accumulation and runoff. However, much of this predictability could disappear with the climate change »notes Will Wieder, a researcher, in a press release from NCAR/Ucar. In case our emissions of greenhouse gases were to continue at the current rate.

Less snow makes the system unpredictable

For a long time now, researchers have pointed out that the coat snow tends to thin and melt sooner as a result of global warming because precipitation falls more as rain than snow. The meltingoccurs in winter . More randomly. Runoff becomes unpredictable and, in its wake, the flow of waterways.

The main impact will be regions such as the Rocky Mountains — where the amount of water contained in the snowpack could decrease by 80% — the Canadian Arctic, eastern North America and Eastern Europe. The management of fresh water resourcescould be very complicated. Both for society and for ecosystems. “Our efforts to improve our predictive models are being shattered by the rapid disappearance of our best ally, snow.explains Flavio Lehner, professor at Cornell University (United States). It may be a race that we are losing, but we are trying to regain the advantage by studying these subjects better”.

A way once again to underline how precious water resources are and should be preserved. Bearing in mind that the most severe impacts on snowpack, runoff and ecosystems can still be avoided if our society ultimately succeeds in reducing its greenhouse gas emissions.