Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

World Ocean Systems Undermined by Climate Change by 2100

17.10.2013
Scientists warn against the high risk of degradation of marine ecosystems and associated human hardships

An ambitious new study that includes Lisa Levin of Scripps Institution of Oceanography at UC San Diego describes the full chain of events by which ocean biogeochemical changes triggered by manmade greenhouse gas emissions may cascade through marine habitats and organisms, penetrating to the deep ocean and eventually influencing humans.

Previous analyses have focused mainly on ocean warming and acidification, considerably underestimating the biological and social consequences of climate change. Factoring in predictable synergistic changes such as the depletion of dissolved oxygen in seawater and a decline in productivity of ocean ecosystems, the new study shows that no corner of the world ocean will be untouched by climate change by 2100.

“When you look at the world ocean, there are few places that will be free of changes; most will suffer the simultaneous effects of warming, acidification, and reductions in oxygen and productivity,” said lead author Camilo Mora, a former Scripps postdoctoral researcher and now an assistant professor at the Department of Geography in the College of Social Sciences at the University of Hawai‘i at Mânoa (UH Mânoa). “The consequences of these co-occurring changes are massive—everything from species survival, to abundance, to range size, to body size, to species richness, to ecosystem functioning are affected by changes in ocean biogeochemistry.”

The human ramifications of these changes are likely to be massive and disruptive. Food chains, fishing, and tourism could all be impacted. The study shows that some 470 to 870 million of the world’s poorest people rely on the ocean for food, jobs, and revenues, and live in countries where ocean goods and services could be compromised by multiple ocean biogeochemical changes.

“Because many deep-sea ecosystems are so stable, even small changes in temperature, oxygen, and pH may lower the resilience of deep-sea communities,” said co-author Levin, a professor at Scripps and director of the Center for Marine Biodiversity and Conservation at Scripps. “This is a growing concern as humans extract more resources and create more disturbances in the deep ocean.”

Mora and Craig Smith with UH Mânoa’s School of Ocean and Earth Science and Technology (SOEST) worked with a 28-person international collaboration of climate modelers, biogeochemists, oceanographers, and social scientists to develop the study, which is published in the scientific journal PLOS Biology.

The researchers used the most recent and robust models of projected climate change developed for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) to inform their analysis. They quantified the extent of co-occurrence of changes in temperature, pH, oxygen, and primary productivity based on two scenarios: a business-as-usual scenario wherein atmospheric CO2 concentrations could reach 900 ppm by 2100, and an alternative scenario under which concentrations only reach 550 ppm by 2100 (representing a concerted, rapid CO2 mitigation effort, beginning today).

They discovered that most of the world’s ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. Only a very small fraction of the oceans, mostly in polar regions, will face the opposing effects of increases in oxygen or productivity, and nowhere will there be cooling or pH increase.

“Even the seemingly positive changes at high latitudes are not necessary beneficial. Invasive species have been immigrating to these areas due to changing ocean conditions and will threaten the local species and the humans who depend on them,” said co-author Chih-Lin Wei, a postdoctoral fellow at Ocean Science Centre, Memorial University of Newfoundland, Canada.

The researchers assembled global distribution maps of 32 marine habitats and biodiversity hotspots to assess their potential vulnerability to the changes. As a final step, they used available data on human dependency on ocean goods and services and social adaptability to estimate the vulnerability of coastal populations to the projected ocean biogeochemical changes.

“Other studies have looked at small-scale impacts, but this is the first time that we’ve been able to look the entire world ocean and how co-occurring stressors will differentially impact the earth’s diverse habitats and people,” said co-author Andrew Thurber, a Scripps alumnus and now a postdoctoral fellow at Oregon State University. “The real power is in the quantitative, predictive approach using IPCC climate models that allow us to see how much it will all change, and also how confident we can be in our estimates.”

By 2100, global averages for the upper layer of the ocean could experience a temperature increase of 1.2 to 2.6° C, a dissolved oxygen concentration reduction of ~2% to 4% of current values, a pH decline of 0.15 to 0.31, and diminished phytoplankton production by ~4% to 10% from current values. The seafloor was projected to experience smaller changes in temperature and pH, and similar reductions in dissolved oxygen.

Of the many marine habitats analyzed in the study, researchers found that coral reefs, seagrass beds, and shallow soft-bottom benthic habitats would experience the largest absolute changes in ocean biogeochemistry, while deep-sea habitats would experience the smallest changes.

“The deep-sea floor covers most of the Earth’s surface and provides a whole host of important ecosystem services including carbon sequestration in seafloor sediments, buffering of ocean acidity, and providing an enormous reservoir of biodiversity,” said Smith. “Nonetheless, very little attention has been paid to modeling the effects of climate change on these truly vast ecosystems. Perhaps not surprisingly, many deep seafloor ecosystems appear susceptible to the effects of climate warming over the next century.”

“The impacts of climate change will be felt from the ocean surface to the seafloor. It is truly scary to consider how vast these impacts will be,” said co-author Andrew K. Sweetman, who helped to convene the original team of investigators and now leads the deep-sea ecosystem research group at the International Research Institute of Stavanger, Norway. “This is one legacy that we as humans should not be allowed to ignore.”

Funding for this study was provided by SeaGrant Hawai‘i, the Norwegian Research Council, and the International Network for scientific investigation of DEEP-sea ecosystems (INDEEP). The authors extend their thanks to the University of Washington and its Friday Harbor Laboratories for hosting the original May 2012 workshop on synergistic climate change impacts at the deep-sea floor (CLiDEEP) that precipitated this study.

Mario Aguilera | Newswise
Further information:
http://www.ucsd.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dune ecosystem modelling
23.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>