Global freshwater consumption crossing its planetary boundary

Planetary boundaries have been proposed to describe a safe operating space of humanity. Human consumption of freshwater is the used control variable for a freshwater planetary boundary. Research from Stockholm University is now showing that global freshwater consumption has already pushed beyond its boundary. The article is published in Science.

The new results account for the freshwater effects of different types of human activity over the twentieth century until present time, including effects of changes in land use (e.g., intensified or extended agriculture, deforestation) and water use (e.g., related to hydropower development). These activities have led to an increased loss of freshwater to the atmosphere due to human-driven increase of evapotranspiration, which includes evaporation from surface and soil water and transpiration by plants. On average over the Earth’s land surface, the combined effect of the different human activities is a net consumption of freshwater, which is greater than the freshwater planetary boundary.

Climate change also drives freshwater changes. Parallel new results, which were also published by Fernando Jaramillo and Georgia Destouni, in Geophysical Research Letters (December 2014), show that climate-driven and direct human-driven changes in evapotranspiration counteract each other globally and in most continents. This counteraction dampens the net total freshwater change, compared to only climate-driven change or only human-driven consumption.

“These results put into question an isolated use of only human water consumption as a freshwater planetary boundary”, says Georgia Destouni, professor at the Department of Physical Geography, Stockholm University.

In summary, the new results are more alarming than previous assessments of the freshwater planetary boundary but less alarming for net global freshwater change. The latter is due to the found dampening effect.

“The new results show that estimates of global freshwater consumption are still highly uncertain”, says Fernando Jaramillo, researcher at the Department of Physical Geography, Stockholm University.

In combination, the results should raise awareness on the high current level of human freshwater consumption, and guide new efforts for reducing the uncertainty about both human freshwater consumption and climate-driven freshwater change.

Link to open access paper in Science Magazine (open access):

http://www.sciencemag.org/content/348/6240/1217.3.full

Link to open access paper in Geophysical Research Letters (open access): http://onlinelibrary.wiley.com/doi/10.1002/2014GL061848/full

Senast uppdaterad: 6 juli 2015
Sidansvarig: External Relations and Communications Office

Tipsa

Contact

Climate, Seas and Environment

Videos

Guillemots add knowledge about the ecosystem puzzle Henrik Österblom, Associate Professor in Environmental Sciences at Stockholm Resilience Centre.
The challenges that lie ahead after leg 1, SWERUS-C3 Örjan Gustafsson, professor in Biogeochemistry Stockholm University.
From permafrost thawing to the venting of greenhouse gases Martin Jakobsson, Professor at the Department for Geological Sciences.
Rotation in Barrow, Swerus-C3 Leg 2 The second leg, which starts from Barrow, is led by Martin Jakobsson, Professor at the Department for Geological Sciences (IGV), Stockholm University.
Collapsing Ice Martin Jakobsson, Professor at the Department for Geological Sciences.
Storglaciären- the end-of-year account At Tarfala Research Station, we carry out the the world's most detailed study of how a glacier changes. In this film we follow the work in September, just before the first snow falls.
Sweden and International Polar Research Stockholm University Researchers have played leading roles in a number of Polar expeditions that have taken place as part of the International Polar Year (IPY - spans 2007-2009).
Arctic foxes Tomas Meijer
Arctic Sweden, Archeology Andreas Viberg, Kerstin Lindén.
Hydrocarbons in Siberia Örjan Gustafsson and Jorien Vonk