Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How much does groundwater contribute to sea level rise?

03.05.2016

Land water, including groundwater extraction, contributes far less to sea level rise than previously thought, according to a new study.

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.


© haveseen | Adobe Stock Photo

Quelle: IIASA

“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.”

Reference
Wada Y, Lo MH, Yeh PJF, Reager JT, Famiglietti JS, Wu RJ, Tseng YH (2016). Fate of water pumped from underground and contributions to sea-level rise. Nature Climate Change. doi:10.1038/NCLIMATE3001

About IIASA:
The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, Europe, and Oceania. www.iiasa.ac.at 

Katherine Leitzell | idw - Informationsdienst Wissenschaft
Further information:
http://www.iiasa.ac.at/web/home/about/news/160502-sealevel.html

More articles from Earth Sciences:

nachricht Research sheds new light on forces that threaten sensitive coastlines
24.04.2017 | Indiana University

nachricht NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>