Climate change is putting 40% more people across the world at risk of water scarcity because of changes in rainfall and evaporation, a new study has found.
Future population growth is not the only factor to put pressure on water availability, says the study, which used impact models to assess how the scenario on water access would change with or without climate change.
Between one and two out of 100 people today live in absolute water scarcity – which means less than 500 cubic metres are available per year and person. Pressure of population growth and climate change will increase the number of people affected to ten.
Lead author of the study Jacob Schewe of the Potsdam Institute for Climate Impact Research in the Netherlands said, “The steepest increase of global water scarcity might happen between 2C and 3C global warming above pre-industrial levels, and this is something to be experienced within the next few decades unless emissions get cut soon.
“It is well-known that water scarcity increases, but our study is the first to quantify the relative share that climate change has in that, compared to – and adding to – the increase that is simply due to population growth.”
The research – which assumed a 2.7C warming increase – identifies the Mediterranean, Middle East, the southern US, and southern China as areas that will see a significant decrease of the water available.
Since water is essential to agriculture and food production, the less availability of water resources might lead to an increase of hunger in some parts of the world.
Schewe added, “From a scientific point of view, climate change can definitely still be delayed. Global warming could be limited to about 1.5C, which in turn would prevent a good part of the developments impacting water resources.”