Subscribe free to our newsletters via your
. Earth Science News .




Subscribe free to our newsletters via your




















WATER WORLD
How much does groundwater contribute to sea level rise?
by Staff Writers
Laxenburg, Austria (SPX) May 08, 2016


Land water contributions are small in comparison to the contribution of ice melt and thermal expansion, yet they have been increasing, leading to concerns that this could exacerbate the problem of sea level rise caused by climate change.

Groundwater extraction and other land water contribute about three times less to sea level rise than previous estimates, according to a new study published in the journal Nature Climate Change. The study does not change the overall picture of future sea level rise, but provides a much more accurate understanding of the interactions between water on land, in the atmosphere, and the oceans, which could help to improve future models of sea level rise.

"Projecting accurate sea level rise is important, because rising sea level is a threat to people who live near the ocean and in small islands," explains IIASA researcher Yoshihide Wada, who led the study. "Some low-lying areas will have more frequent flooding, and very low-lying land could be submerged completely. This could also damage substantially coastal infrastructure."

Sea level has risen 1.7 mm per year over the 20th and the early 21st century, a trend that is expected to continue as climate change further warms the planet. Researchers have attributed the rising seas to a combination of factors including melting ice caps and glaciers, thermal expansion (water expands as it gets warmer), and the extraction of groundwater for human use.

Land water contributions are small in comparison to the contribution of ice melt and thermal expansion, yet they have been increasing, leading to concerns that this could exacerbate the problem of sea level rise caused by climate change.

However, much uncertainty remains about how much different sources contribute to sea level rise. In fact, sea level has actually risen more than researchers could account for from the known sources, leading to a gap between observed and modeled global sea-level budget.

Previous studies, including estimates used in the IPCC Fifth Assessment Report, had assumed that nearly 100% of extracted groundwater ended up in the ocean. The new study improves on previous estimates by accounting for feedbacks between the land, ocean, and atmosphere. It finds that number is closer to 80%. That means that the gap between modeled and observed sea level rise is even wider, suggesting that other processes are contributing more water than previously estimated.

"During the 20th century and early 21st century, cumulative groundwater contribution to global sea level was overestimated by at least 10 mm," says Wada. In fact, the new study shows that from 1971 to 2010, the contribution of land water to global sea level rise was actually slightly negative - meaning that more water was stored in groundwater and also due to reservoir impoundment behind dams. From 1993 to 2010, the study estimates terrestrial water as contributing positive 0.12 mm per year to sea level rise.

The study does not change the fact that future groundwater contribution to sea level will increase as groundwater extraction increases. And the increasing trend in groundwater depletion has impacts beyond sea level rise. Wada explains, "The water stored in the ground can be compared to money in the bank. If you withdraw money at a faster rate than you deposit it, you will eventually start having account-supply problems. If we use groundwater unsustainably, in the future there might not be enough groundwater to use for food production. Groundwater depletion can also cause severe environmental problems like reduction of water in streams and lakes, deterioration of water quality, increased pumping costs, and land subsidence."

.


Related Links
International Institute For Applied Systems Analysis
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
WATER WORLD
Obama drinks water in Flint, hits Republicans
Flint, United States (AFP) May 4, 2016
A combative President Barack Obama visited crisis-hit Flint, Michigan, Wednesday where he conspicuously sipped filtered water to prove it was potable and attacked "corrosive" Republican attitudes toward "big government." More than 8,000 children are believed to have consumed lead-contaminated water in the hardscrabble northern city, which has become a focus of the 2016 election campaign. ... read more


WATER WORLD
Four rescued six days after Kenya building collapse

Chile quake at epicenter of expanding disaster and failure data repository

Kenya building collapse toll rises to 21

Personal cooling units on the horizon

WATER WORLD
Cavitation intensity enhanced using pressure at bubble collapse region

Hybrid nanoantennas offer new platform for ultradense data recording

Squished cells could shape design of synthetic materials

Engineers create a better way to boil water

WATER WORLD
A cleansing rain falls; a soil-filled mist arises

Reef system with 10,000 km2 found at the Amazon River mouth

Hydropeaking of river water levels is disrupting insect survival, rivers

New study found ocean acidification may be impacting Florida keys

WATER WORLD
Ice loss accelerating in Greenland's coastal glaciers

Study finds limit on evaporation to ice sheets, but that may change

Extreme weather linked to high pressure over Greenland

Researchers discover fate of melting glacial ice in Greenland

WATER WORLD
Nanoparticles present sustainable way to grow food crops

A new resource to help manage billbugs in turfgrass

Methane production reduced in ruminants

Bioreactors ready for the big time

WATER WORLD
Floods following drought worsen Ethiopian hunger

Survivor rescued 13 days after deadly Ecuador quake

Survivors sought after 10 killed in Kenya building collapse

Chile ordered to pay $2.7 mn to 2010 tsunami victims

WATER WORLD
Severe drought forces Zimbabwe to sell off wildlife

Kenya torches world's biggest ivory bonfire to save elephants

Senegal signs accord giving US forces permament access to the country

Mozambique police probe reports of mass grave in rebel stronghold

WATER WORLD
Hominins may have been food for carnivores 500,000 years ago

Neandertals and Upper Paleolithic Homo sapiens had different dietary strategies

Chimp study explores the early origins of human hand dexterity

Toward quieting the brain




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement