Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Warmer than a Hot Tub: Atlantic Ocean Temperatures Much Higher in the Past

20.02.2006


Study Suggests Climate Models Underestimate Future Warming



Scientists have found evidence that tropical Atlantic Ocean temperatures may have once reached 107°F (42°C)—about 25°F (14°C) higher than ocean temperatures today and warmer than a hot tub. The surprisingly high ocean temperatures, the warmest estimates to date for any place on Earth, occurred millions of year ago when carbon dioxide levels in Earth’s atmosphere were also high, but researchers say they may be an indication that greenhouse gases could heat the oceans in the future much more than currently anticipated. The study suggests that climate models underestimate future warming.

“These temperatures are off the charts from what we’ve seen before,” said Karen Bice, a paleoclimatologist at Woods Hole Oceanographic Institution (WHOI). Bice reported the findings Feb. 17 at the annual meeting of the American Association for the Advancement of Science (AAAS) in St. Louis and is also lead author of a study to be published in an upcoming issue of the journal Paleoceanography, published by the American Geophysical Union.


Bice and a multi-institutional team of scientists studied three long columns of sediment cored from the seafloor in 2003 off Suriname, on the northeast coast of South America, by the drillship JOIDES Resolution, operated by the international Ocean Drilling Program.

The sediments contained an unusually rich and well-preserved accumulation of both carbon-rich organic matter and the fossilized shells of microscopic marine organisms that had settled and piled up on the seafloor over tens of millions of years. The deeper down in the core the scientists analyzed, the further back in time they went.

The team analyzed the shells’ isotopic and trace element chemistry, which changes along with temperature changes in the surface waters where they lived. They determined that ocean temperatures in the region ranged between 91° and 107°F (33° and 42°C) between 84 million and 100 million years ago in an era when dinosaurs roamed the Earth. Temperatures range between 75° and 82°F (24° and 28°C) in the same region now. The approximate uncertainty in the paleotemperature estimates is +/-2°C.

Using organic matter from the sediments, the group also estimated atmospheric carbon dioxide concentrations during the same time span. They were 1,300 to 2,300 parts per million (ppm), compared with 380 ppm today.

The findings, if confirmed, create a dilemma for scientists seeking to forecast how Earth’s climate and environment will change in response to the rising amounts of heat-trapping carbon dioxide in the atmosphere, caused by deforestation and the burning of oil, coal, and other fossil fuels. When 1,300 to 2,300 ppm of carbon dioxide is factored into current computer models that simulate global climate, it does not produce such high ocean temperatures.

“The climate models underestimate temperatures and the amount of warming that would accompany an increase in CO2 of more than 1,000 ppm above today’s level.” Bice said..

If the scientists’ interpretations of past ocean temperatures and carbon dioxide levels prove accurate, actual future warming from elevated atmospheric carbon dioxide concentrations may be much greater than predicted by the models, the scientists reported.

“One of the most important impacts this evidence suggests is the change to the Earth’ hydrologic cycle,” Bice said. “Higher tropical temperatures will increase the intensity of hurricanes and winter storms. In addition, precipitation patterns will change, moving even more rain that now falls on the central U.S. - an area known as the breadbasket of the U.S. for its food production - to higher latitudes where the quality of the soil may not be as conducive to agriculture”

“Policymakers use these models to predict likely climate change with increasing CO2 levels, and if the models are not right, society is not well informed or well served.”

Alternatively, the models used to predict future climate may be missing a critical factor that amplifies heating, Bice said. During past warm periods, oceans and wetlands may have released much more methane gas to the atmosphere. Methane traps heat 10 times more effectively than carbon dioxide.

However, extraordinarily high concentrations of methane in the model still fail to produce the tropical Atlantic and Arctic Ocean temperatures inferred for 91 million years ago. This supports the idea that the model’s response to increased greenhouse gas concentrations underestimates the actual climate system’s response.

The research team included Bice and Kristina Dahl of WHOI, Philip A. Meyers of the University of Michigan, Daniel Birgel and Kai-Uwe Hinrichs of the University of Bremen, and Richard D. Norris of Scripps Institution of Oceanography. Bice’s work was supported by private funding from the Woods Hole Oceanographic Institution through the Ocean and Climate Change Institute and The Andrew W. Mellon Foundation Endowed Fund for Innovative Research. Funding for this research was also provided by the Joint Oceanographic Institutions U.S. Science Support Program and Deutsche Forschungsgemeinschaft through the DFG-Research Center Ocean Margins.

Shelley Dawicki | EurekAlert!
Further information:
http://www.whoi.edu

More articles from Earth Sciences:

nachricht Novel method for investigating pore geometry in rocks
17.06.2018 | Kyushu University, I2CNER

nachricht Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive

15.06.2018 | Materials Sciences

100 % Organic Farming in Bhutan – a Realistic Target?

15.06.2018 | Ecology, The Environment and Conservation

Perovskite-silicon solar cell research collaboration hits 25.2% efficiency

15.06.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>