Recent Shifts in Global Freshwater Highlight Climate Change Consequences

     A recent study led by a NASA research team, published by the University of Maryland, reported that the freshwater distribution on Earth is getting progressively more divided. Water levels are rising in wet areas and droughts are increasing in dry areas. While this is due to several factors, the data backs climate change, water management practices, and naturally occurring climate cycles, as the key contributors.

     While having to distinguish shifts based on natural effects, such as the wet and dry periods that El Niño and La Niña weather brings, from climate change and human-created impacts, researchers found that the majority of the issues stemmed from human-based climate change. Freshwater sources have been dwindling in recent years, especially with glaciers, housing the largest supply of freshwater, melting and contributing to sea levels rising. Though freshwater supplies in lakes, rivers, groundwater, etc. may fluctuate regularly, this study showed a concerning new pattern.

     Launched in 2002 as a joint mission with the German Aerospace Center, the twin GRACE satellites tracked the movements of terrestrial water storage through October 2017. Though it revealed that there were significant changes of freshwater storages and obvious in many areas that climate-change was the cause of these effects, more time and data will be needed to prove that it’s the main culprit. However, it did show the clear pattern of wet areas becoming wetter and dry areas becoming drier, especially in dry areas where several areas were suffering from groundwater depletion.

     Areas such as California showed the most depletion of groundwater, with the severe drought from 2007 to 2015 and use of much of the remaining water for agricultural purposes cited as the main causes. Southwestern California especially, lost four gigatons of freshwater a year, an amount equivalent to the water in 400,000 Olympic swimming pools. Most of California’s water comes from the rain and snow in the Sierra Nevadas, however when natural cycles caused dry periods, less rain and snow were produced and thus people turned to groundwater.

     The study concluded that a combination of natural and human-based factors have contributed to such distressing results. However, the successor to GRACE, GRACE Follow-On, is currently at Vandenberg Air Force Base in California, getting ready to be launched and provide the final data to cement that climate-change is the culprit of this increasingly concerning issue.

     To learn more about this study on the recent trends of freshwater, please visit https://www.sciencedaily.com/r...


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