Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dramatic climate change is unpredictable

31.08.2010
The fear that global temperature can change very quickly and cause dramatic climate changes that may have a disastrous impact on many countries and populations is great around the world. But what causes climate change and is it possible to predict future climate change?

New research from the Niels Bohr Institute at the University of Copenhagen shows that it may be due to an accumulation of different chaotic influences and as a result would be difficult to predict. The results have just been published in Geophysical Research Letters.

For millions of years the Earth's climate has alternated between about 100,000 years of ice age and approximately 10-15,000 years of a warm climate like we have today. The climate change is controlled by the Earth's orbit in space, that is to say the Earth's tilt and distance from the sun. But there are also other climatic shifts in the Earth's history and what caused those?

Dramatic climate change of the past

By analysing the ice cores that are drilled through the more than three kilometer thick ice sheet in Greenland, scientists can obtain information about the temperature and climate going back around 140,000 years.

The most pronounced climate shifts besides the end of the ice age is a series of climate changes during the ice age where the temperature suddenly rose 10-15 degrees in less than 10 years. The climate change lasted perhaps 1000 years, then - bang – the temperature fell drastically and the climate changed again. This happened several times during the ice age and these climate shifts are called the Dansgaard-Oeschger events after the researchers who discovered and described them. Such a sudden, dramatic shift in climate from one state to another is called a tipping point. However, the cause of the rapid climate change is not known and researchers have been unable to reproduce them in modern climate models.

The climate in the balance

"We have made a theoretical modelling of two different scenarios that might trigger climate change. We wanted to investigate if it could be determined whether there was an external factor which caused the climate change or whether the shift was due to an accumulation of small, chaotic fluctuations", explains Peter Ditlevsen, a climate researcher at the Niels Bohr Institute.

He explains that in one scenario the climate is like a seesaw that has tipped to one side. If sufficient weight is placed on the other side the seesaw will tip – the climate will change from one state to another. This could be, for example, an increase in the atmospheric content of CO2 triggering a shift in the climate.

In the second scenario the climate is like a ball in a trench, which represents one climate state. The ball will be continuously pushed by chaos-dynamical fluctuations such as storms, heat waves, heavy rainfall and the melting of ice sheets, which affect ocean currents and so on. The turmoil in the climate system may finally push the ball over into the other trench, which represents a different climate state.

Peter Ditlevsen's research shows that you can actually distinguish between the two scenarios and it was the chaos-dynamical fluctuations that were the triggering cause of the dramatic climate changes during the ice age. This means that they are very difficult to predict.

Warm future climate

But what about today – what can happen to the climate of the future? "Today we have a different situation than during the ice age. The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago, when the climate was very warm and alligators lived in England. So we have already started tilting the seesaw and at the same time the ball is perhaps getting kicked more and could jump over into the other trench. This could mean that the climate might not just slowly gets warmer over the next 1000 years, but that major climate changes theoretically could happen within a few decades", estimates Peter Ditlevsen, but stresses that his research only deals with investigating the climate of the past and not predictions of the future climate.

Contact:

Peter Ditlevsen, climate researcher, PhD. Dr. Scient., Associate professor, Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, +45 3532-0603, +45 2875-0603, pditlev@gfy.ku.dk

Link to article in Geophysical Research Letters: http://www.agu.org/journals/gl/papersinpress.shtml#id2010GL044486

Gertie Skaarup | EurekAlert!
Further information:
http://www.nbi.dk

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>