Less than 6% of groundwater is replenished within 50 years, and renewable sources are finite and limited.
(Newswire.net — November 18, 2015) –Victoria, Canada – According to a new Canadian-led study, we could easily run out of water supply, since the wells we rely on cannot be renewed. It is a common belief that snow and rain do their job effectively to kindly provide us with fresh water, but it turns out that resources previously considered renewable aren’t all that renewable.
Only six percent of groundwater is renewed during the period of 50 years, which is definitely alarming, according to a new study published in the journal Nature Geoscience today.
This is basically due to the fact that water is usually found close to the surface, only a few hundred meters down, and for that reason it is very susceptible to contamination and loss due to high temperatures. The problem is further compounded by a reduced rainfall.
“Groundwater is a super-important resource. It’s used by more than a third of the world’s population every day for their drinking water and it’s used by agriculture and industry,” Tom Gleeson, one of the top scientists, said in an interview with CBC News.
According to the study, Canadians, for example, should be very worried, since more than a third of the Canadian population seems to rely on groundwater, including the entire population of P.E.I. and some fairly large urban centers such as Kitchener-Waterloo, Cambridge and Guelph in Ontario.
Being of utmost importance to us all, Gleeson and his colleagues rolled up their sleeves and tried to establish how much, and where, groundwater can be found, and accordingly – how much longer we will be able to use it. Certain rough estimates of the amount of groundwater had already been made, but so far it has not been ascertained how much of it can be renewed.
Gleeson and his colleagues figured out where groundwater was less than 50 years old. It turns out that, due to nuclear testing in the 1960s, a radioactive form of hydrogen called tritium first appeared in the world’s water supply. The point was to determine, by taking samples from 55 countries and using computer models to follow groundwater around the world, “which” water is young and renewable and which is old and still contaminated. It seems that rocks contribute much when it comes to water storage, so we should not ignore and underestimate their importance, too.
The outcome is as follows: it is estimated that there is enough water to cover all the land on Earth to a depth of 180 meters, which means that there is less than six per cent of renewable water. In the next 50 years it will be quite enough to cover all land on Earth to a depth of just three meters. That’s bad news. Fortunately for us, there is also some good news, since the research shows that the amount of groundwater on the whole planet is three times larger than all other fresh water from the rivers and lakes, which buys us some additional time. The trouble is, this water is not distributed evenly, so in some places like California and the U.S. Midwest, people are already using the “non-renewable” water that is thousands of years old. In places such as Egypt, they use much saltier and more contaminated water that may have last been renewed a million years ago.