For years, scientists have thought that a continental ice sheet formed during the Late Cretaceous Period more than 90 million years ago when the climate was much warmer than it is today.
Now, a University of Missouri researcher has found evidence suggesting that no ice sheet formed at this time. This finding could help environmentalists and scientists predict what the earth's climate will be as carbon dioxide levels continue to rise.
"Currently, carbon dioxide levels are just above 400 parts per million (ppm), up approximately 120 ppm in the last 150 years and rising about 2 ppm each year," said Ken MacLeod, a professor of geological sciences at MU. "In our study, we found that during the Late Cretaceous Period, when carbon dioxide levels were around 1,000 ppm, there were no continental ice sheets on earth. So, if carbon dioxide levels continue to rise, the earth will be ice-free once the climate comes into balance with the higher levels."
Previously, many scientists have thought that doubling CO2 levels would cause earth's temperature to increase as much as 3 degrees Celsius, or approximately 6 degrees Fahrenheit. However, the temperatures MacLeod believes existed in Tanzania 90 million years ago are more consistent with predictions that a doubling of CO2 levels would cause the earth's temperature could rise an average of 6 degrees Celsius, or approximately 11 degrees Fahrenheit.
"While studying the past can help us predict the future, other challenges with modern warming still exist," MacLeod said. "The Late Cretaceous climate was very warm, but the earth adjusted as changes occurred over millions of years. We're seeing the same size changes, but they are happening over a couple of hundred years, maybe 10,000 times faster. How that affects the equation is a big and difficult question."
MacLeod's study was published in the October issue of the journal Geology.
Christian Basi | EurekAlert!
GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center
Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz
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...
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...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy