The human impact on the loss of fresh water is 20% higher than estimated – La Jornada (Bolivia)

The human impact on the loss of fresh water, with activities such as irrigation and dam construction, is 20% higher than estimated, according to a new study published in the journal “Science”.

The research concludes that the increase in the total loss of fresh water to the atmosphere by evapotranspiration is 4,370 cubic kilometers, equivalent two thirds of the annual flow of the Amazon River, the largest river in the world.

“The little things we do on the surface of the Earth can have major global effects. Previously, the effects of human activities such as dams were dismissed, this study shows that so far the effects have been even greater than the atmospheric climate change, “said Fernando Jaramillo, postdoctoral Department of Physical Geography at the University of Stockholm. The thesis of this study is that activities such as irrigation and dams have greatly increased the global human consumption of fresh water by increasing evapotranspiration, that is, the loss of moisture from a surface by direct evaporation along with water loss through transpiration vegetation. The human impact increases the loss of fresh water into the atmosphere and, therefore, reduce the water available to human societies and ecosystems. “The increase in the loss due to human causes is like a huge river of fresh water on Earth into the atmosphere. We have changed both the fresh water system without knowing it” considers Gia Destouni, professor at Stockholm University. “We have already exceeded the limits of the consumption of fresh water on the planet, this is serious, whether we have crossed a real limit or the limit is underestimated,” adds Destouni. To carry out this research, the scientists analyzed data on climate, hydrology and water use in hundreds of large watersheds in the world between 1901 and 2008.