The study is published in the journal Nature Geoscience. The scientists used a computer model developed at the Danish Centre for Earth System Science (DCESS) that analyses global changes extending 100,000 years into the future.
The DCESS model includes atmosphere, ocean, ocean-sediment, land-biosphere and lithosphere modules. According to the study, it reproduces 'observed evolutions since 1765 of key climate metrics including atmosphere and ocean warming, atmospheric gas contents and ocean and land-biosphere CO2 uptakes'.
Two emissions scenarios of the Intergovernmental Panel on Climate Change (IPCC) were evaluated: one with a moderate (3°C) temperature increase and one with a high (4.8°C) temperature rise. In both simulations, there was oxygen loss in the upper 500m of the ocean, largely in response to surface-layer warming. Importantly, overturning circulation in the deep ocean, which pulls oxygenated surface waters down to the depths of the ocean, decreased. The high-emissions scenario in particular predicted 'severe, long-term ocean oxygen depletion,' and it was clear that the suboxic regions of the ocean, which are void of fish and other larger creatures, would expand in both cases.
Observations in the oceans already show that suboxic areas are expanding as the atmosphere and ocean warm. In line with this and other supporting observations, the model projects a three- to seven-fold expansion in suboxic zones. The authors explain that as suboxic zones expand, different microbes and plankton take over. This forces a shift towards nitrogen fixers, which the researchers say would probably force large, unpredictable changes in ocean ecosystem structure and productivity, with serious consequences.
The study's conclusions are simple: 'Reduced fossil-fuel emissions would be needed to limit ongoing oxygen depletion and its long-term adverse effects.'
Extreme oceanic oxygen depletion events are thought to be behind some of the large extinction events in the Earth's history, including the largest such event 250 million years ago.
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses