Major declines in global freshwater recorded

17th May 2018


Web drought istock 157313406

Related Topics

Related tags

  • Global ,
  • Water ,
  • Flood ,
  • Scarcity

Author

John Stanley Williams

There have been significant declines in the amount of freshwater recorded in various hotspots around the world during the 21st century, NASA satellite observations have found.

This is thought to be due to a variety of possible factors, including human water management systems, climate change and natural cycles, although it is not entirely clear what is causing the apparent trends.

Southwestern California lost four gigatons of freshwater per year between 2007 and 2015 – with one gigaton able to fill 400,000 Olympic swimming pools – while Saudi Arabia lost 6.1 annually between 2002 and 2016.

The researchers noted that the earth’s wet land areas are getting wetter, while dry areas are getting drier, with some regions’ water supplies relatively stable while others are not.

“What we are witnessing is major hydrologic change,” said Jay Famiglietti, study co-author and researcher at NASA’s Jet Propulsion Laboratory. “Embedded within the dry areas we see multiple hotspots resulting from groundwater depletion.”

The first-of-its-kind study took data from NASA’s Gravity Recovery and Climate Experiment (GRACE) tracking freshwater trends between 2002 and 2016 across the globe.

Although water loss and gains in some regions were concluded to be the result of a warming climate, such as where ice sheets and alpine glaciers melt, others are thought to be due to natural cycles.

Water storage was found to have increased by an average rate of 29 gigatons per year between 2002 and 2016 in Africa’s western Zambezi basin and Okavango Delta, which followed two decades of dryness.

While the Xinjiang province in China experienced an annual 5.5 gigaton loss in terrestrial water storage in the first decades of this century, despite increased surface water caused by a climate change-induced glacier melt.

The Intergovernmental Panel on Climate Change has predicted that wet areas would become wetter and dry ones drier, although it is thought to be too soon to know the reasons behind the latest findings.

“We’ll need a much longer dataset to be able to definitively say whether climate change is responsible for the emergence of any similar pattern in the GRACE data,” Famiglietti added.

Image credit: iStock

Subscribe

Subscribe to IEMA's newsletters to receive timely articles, expert opinions, event announcements, and much more, directly in your inbox.


Transform articles

SBTi clarifies that ‘no change has been made’ to its stance on offsetting

The Science Based Targets initiative (SBTi) has issued a statement clarifying that no changes have been made to its stance on offsetting scope 3 emissions following a backlash.

16th April 2024

Read more

While there is no silver bullet for tackling climate change and social injustice, there is one controversial solution: the abolition of the super-rich. Chris Seekings explains more

4th April 2024

Read more

One of the world’s most influential management thinkers, Andrew Winston sees many reasons for hope as pessimism looms large in sustainability. Huw Morris reports

4th April 2024

Read more

Alex Veitch from the British Chambers of Commerce and IEMA’s Ben Goodwin discuss with Chris Seekings how to unlock the potential of UK businesses

4th April 2024

Read more

Regulatory gaps between the EU and UK are beginning to appear, warns Neil Howe in this edition’s environmental legislation round-up

4th April 2024

Read more

Five of the latest books on the environment and sustainability

3rd April 2024

Read more

Ben Goodwin reflects on policy, practice and advocacy over the past year

2nd April 2024

Read more

In 2020, IEMA and the Institute and Faculty of Actuaries (IFoA) jointly wrote and published A User Guide to Climate-Related Financial Disclosures. This has now been updated to include three key developments in the field.

2nd April 2024

Read more

Media enquires

Looking for an expert to speak at an event or comment on an item in the news?

Find an expert

IEMA Cookie Notice

Clicking the ‘Accept all’ button means you are accepting analytics and third-party cookies. Our website uses necessary cookies which are required in order to make our website work. In addition to these, we use analytics and third-party cookies to optimise site functionality and give you the best possible experience. To control which cookies are set, click ‘Settings’. To learn more about cookies, how we use them on our website and how to change your cookie settings please view our cookie policy.

Manage cookie settings

Our use of cookies

You can learn more detailed information in our cookie policy.

Some cookies are essential, but non-essential cookies help us to improve the experience on our site by providing insights into how the site is being used. To maintain privacy management, this relies on cookie identifiers. Resetting or deleting your browser cookies will reset these preferences.

Essential cookies

These are cookies that are required for the operation of our website. They include, for example, cookies that enable you to log into secure areas of our website.

Analytics cookies

These cookies allow us to recognise and count the number of visitors to our website and to see how visitors move around our website when they are using it. This helps us to improve the way our website works.

Advertising cookies

These cookies allow us to tailor advertising to you based on your interests. If you do not accept these cookies, you will still see adverts, but these will be more generic.

Save and close