(Press-News.org) Variations in atmosphere carbon dioxide around 40 million years ago were tightly coupled to changes in global temperature, according to new findings published in the journal Science. The study was led by scientists at Utrecht University, working with colleagues at the NIOZ Royal Netherlands Institute for Sea Research and the University of Southampton.
"Understanding the relationship between the Earth's climate and atmospheric carbon dioxide in the geological past can provide insight into the extent of future global warming expected to result from carbon dioxide emission caused by the activities of humans," said Dr Steven Bohaty of the University of Southampton's School of Ocean and Earth Science (SOES) based at the National Oceanography Centre in Southampton.
It has been known for some time that the long-term warmth of the Eocene (~56 to 34 million years ago) was associated with relatively high atmospheric carbon dioxide levels. However, scientists were previously unable to demonstrate tight-coupling between variations in atmospheric carbon dioxide and shorter-term changes in global climate.
To fill this gap in knowledge, the authors of the new study focused on one of the hottest episodes of Earth's climate history – the Middle Eocene Climatic Optimum (MECO), which occurred around 40 million years ago.
Algae use photosynthesis to harvest the energy of the sun, converting carbon dioxide and water into the organic molecules required for growth. Different isotopes of carbon are incorporated into these molecules depending on the environmental conditions under which algae grow. Ancient climate can therefore be reconstructed by analysing the carbon isotope ratios of molecules preserved in fossilised algae.
The researchers took this approach to reconstruct variations in carbon dioxide levels across the MECO warming event, using fossilised algae preserved in sediment cores extracted from the seafloor near Tasmania, Australia, by the Ocean Drilling Program. They refined their estimates of carbon dioxide levels using information on the past marine ecosystem derived from studying changes in the abundance of different groups of fossil plankton.
Their analyses indicate that MECO carbon dioxide levels must have at least doubled over a period of around 400,000 years. In conjunction with these findings, analyses using two independent molecular proxies for sea surface temperature show that the climate warmed by between 4 and 6 degrees Celsius over the same period.
"We found a close correspondence between carbon dioxide levels and sea surface temperature over the whole period, suggesting that increased amounts of carbon dioxide in the atmosphere played a major role in global warming during the MECO," said Bohaty.
The researchers consider it likely that elevated atmospheric carbon dioxide levels during the MECO resulted in increased global temperatures, rather than vice versa, arguing that the increase in carbon dioxide played the lead role.
"The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks," said co-lead author Peter Bijl of Utrecht University. "Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth's temperature."
The researchers point out that the large increase in atmospheric carbon dioxide indicated by their analysis would have required a natural carbon source capable of injecting vast amounts of carbon into the atmosphere.
The rapid increase in atmospheric carbon dioxide levels around 40 million years ago approximately coincides with the rise of the Himalayas and may be related to the disappearance of an ocean between India and Asia as a result of plate tectonics – the large scale movements of the Earth's rocky shell (lithosphere). But, as explained by Professor Paul Pearson of Cardiff University in a perspective article accompanying the Science paper, the hunt is now on to discover the exact cause.
INFORMATION:
The researchers are Peter Bijl, Alexander Houben, Appy Sluijs, Henk Brinkhuis, Gert-Jan Reichart (Utrecht University), Jaap Sinninghe Damsté and Stefan Schouten (NIOZ Royal Netherlands Institute of Sea Research) and Steven Bohaty (SOES).
The research was funded by the Netherlands Organization for Scientific Research Utrecht University and Statoil, and used samples and data provided by the Ocean Drilling Program (ODP).
Publication:
Bijl, P. K., Houben, A. J. P., Schouten, S., Bohaty, S. M., Sluijs, A., Reichart, G-J., Sinninghe Damsté, J. S. & Brinkhuis, H. Transient middle Eocene atmospheric CO2 and temperature variations. Science 330, 819 - 8215 (2010).
DOI: 10.1126/science.1193654
http://www.sciencemag.org/cgi/content/full/330/6005/819
Science Perspective:
Pearson, P. N. Increased atmospheric CO2 during the middle Eocene. Science 330, 763-764 (2010). DOI: 10.1126/science.1197894
http://www.sciencemag.org/cgi/content/short/330/6005/763
Extreme global warming in the ancient past
Ancient global warming
2010-11-11
ELSE PRESS RELEASES FROM THIS DATE:
Genes hold key to how well coalitions work, psychologists say
2010-11-11
How well a person performs in a coalition is partly hereditary, according to a recent study.
Researchers found that how successfully an individual operates in a group is as much down to having the right genetic make-up as it is to having common cultural ties with fellow group members.
After assessing nearly 1000 pairs of adult twins, researchers at the University of Edinburgh found that strong genetic influences have a major influence on how loyal a person feels to their social group.
It also has a significant impact on how flexibly they can adapt group membership.
Family ...
Research strengthens evidence of link between paracetamol use in pregnancy and childhood asthma
2010-11-11
Evidence suggesting that the risk of childhood asthma associated with prenatal paracetamol exposure may depend on antioxidant genes in the mother has been found by a team of UK scientists. The results of their study - which strengthens the argument for a causal link between paracetamol exposure in early life and later childhood asthma - are published online (10 November) in the Journal of Allergy and Clinical Immunology.
Led by Seif Shaheen, Professor of Respiratory Epidemiology at Barts and The London School of Medicine and Dentistry, the team examined data from the ...
New ultra-clean nanowires have great potential
2010-11-11
New ultra-clean nanowires produced at the Nano-Science Center, University of Copenhagen will have a central role in the development of new high-efficiency solar cells and electronics on a nanometer scale. PhD student Peter Krogstrup, Niels Bohr Institute, in collaboration with a number of well-known researchers and the company SunFlake A/S, is behind the breakthrough. The new findings have recently been published in the prestigious journal Nano Letters.
Nanowires are one-dimensional structures with unique electrical and optical properties – a kind of building blocks, ...
Robust methods for GMO detection ready at hand
2010-11-11
A new Reference Report published today by the European Commission's Joint Research Centre (JRC) lists 79 reference methods for GMO analysis which have been validated according to international standards. This Compendium, developed jointly by the European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF) and the European Network of GMO Laboratories (ENGL), presents the technical state of the art in GMO detection methods. Each method is described in a user-friendly way, facilitating the implementation of GMO legislation by official control bodies.
Presenting ...
University research reveals deaf adults see better than hearing people
2010-11-11
Adults born deaf react more quickly to objects at the edge of their visual field than hearing people, according to groundbreaking new research by the University of Sheffield.
The study, which was funded by the Royal National Institute for Deaf People (RNID), has, for the first time ever, seen scientists test how peripheral vision develops in deaf people from childhood to adulthood.
Dr Charlotte Codina, from the University's Academic Unit of Ophthalmology and Orthoptics, led the research and found that children born deaf are slower to react to objects in their peripheral ...
Cancer news articles may contribute to confusion about cancer
2010-11-11
New research from North Carolina State University shows that most online news stories about cancer contain language that likely contributes to public uncertainty about the disease – a significant finding, given that at least one-third of Americans seek health information online.
"Previous studies show that more than 100 million Americans seek health information online, and that their findings affect their health decisions," says Dr. Kami Kosenko, an assistant professor of communication at NC State and co-author of a paper describing the study. "But, while people facing ...
New highly stable fuel-cell catalyst gets strength from its nano core
2010-11-11
UPTON, NY - Stop-and-go driving can wear on your nerves, but it really does a number on the precious platinum that drives reactions in automotive fuel cells. Before large fleets of fuel-cell-powered vehicles can hit the road, scientists will have to find a way to protect the platinum, the most expensive component of fuel-cell technology, and to reduce the amount needed to make catalytically active electrodes.
Now, scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have developed a new electrocatalyst that uses a single layer of platinum ...
Infant foods should be screened for mycotoxins
2010-11-11
ANTWERP – An international team of scientists calls for protecting complementary food for infants in developing countries – especially those where corn is a staple food – against fumonisin, a toxin produced by fungi. Until now, physicians thought the growth retardation of children in those regions was to be blamed on the poor nutritional value of the complementary maize porridge they receive when breast milk is no longer sufficient. But toxins indeed are involved, the scientists report in the journal Molecular Nutrition and Food Research.
The call is made by scientists ...
Georgia Tech keeps high performance computing sights set on exascale at SC10
2010-11-11
The road to exascale computing is a long one, but the Georgia Institute of Technology, a new leader in high-performance computing research and education, continues to win new awards and attract new talent to drive technology innovation. From algorithms to architectures and applications, Georgia Tech's researchers are collaborating with top companies, national labs and defense organizations to solve the complex challenges of tomorrow's supercomputing systems. Ongoing projects and new research initiatives spanning several Georgia Tech disciplines directly addressing core ...
Dietary intervention can prevent the disease process leading to Type 1 diabetes
2010-11-11
A Finnish study confirms the hypothesis that infant feeding plays a role in the initiation of the disease process leading to type 1 diabetes in children carrying increased genetic disease risk.
The study population comprised 230 newborn infants with at least one family member affected by type 1 diabetes and a predisposing genotype based on screening cord blood at birth. The participants were randomized into two groups; the infants in the intervention group were weaned to a highly hydrolyzed casein-based formula (Nutramigen, Mead Johnson Nutrition), while those in the ...
LAST 30 PRESS RELEASES:
Less intensive works best for agricultural soil
Arctic rivers project receives “national champion” designation from frontiers foundation
Computational biology paves the way for new ALS tests
Study offers new hope for babies born with opioid withdrawal syndrome
UT, Volkswagen Group of America celebrate research partnership
New Medicare program could dramatically improve affordability for cancer drugs – if patients enroll
Are ‘zombie’ skin cells harmful or helpful? The answer may be in their shapes
University of Cincinnati Cancer Center presents research at AACR 2025
Head and neck, breast, lung and survivorship studies headline Dana-Farber research at AACR Annual Meeting 2025
AACR: Researchers share promising results from MD Anderson clinical trials
New research explains why our waistlines expand in middle age
Advancements in muon detection: Taishan Antineutrino Observatory's innovative top veto tracker
Chips off the old block
Microvascular decompression combined with nerve combing for atypical trigeminal neuralgia
Cutting the complexity from digital carpentry
Lung immune cell type “quietly” controls inflammation in COVID-19
Fiscal impact of expanded Medicare coverage for GLP-1 receptor agonists to treat obesity
State and sociodemographic trends in US cigarette smoking with future projections
Young adults drive historic decline in smoking
NFCR congratulates Dr. Robert C. Bast, Jr. on receiving the AACR-Daniel D. Von Hoff Award for Outstanding Contributions to Education and Training in Cancer Research
Chimpanzee stem cells offer new insights into early embryonic development
This injected protein-like polymer helps tissues heal after a heart attack
FlexTech inaugural issue launches, pioneering interdisciplinary innovation in flexible technology
In Down syndrome mice, 40Hz light and sound improve cognition, neurogenesis, connectivity
Methyl eugenol: potential to inhibit oxidative stress, address related diseases, and its toxicological effects
A vascularized multilayer chip reveals shear stress-induced angiogenesis in diverse fluid conditions
AI helps unravel a cause of Alzheimer's disease and identify a therapeutic candidate
Coalition of Autism Scientists critiques US Department of Health and Human Services Autism Research Initiative
Structure dictates effectiveness, safety in nanomedicine
Mission accomplished for the “T2T” Hong Kong Bauhinia Genome Project
[Press-News.org] Extreme global warming in the ancient pastAncient global warming