Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

What Is Guilty Of Warming: Methane Or Carbonic Acid Gas?

10.07.2007
Back in the early 1990s, researchers found that the earth's surface temperature increased rather quickly by 5 to 9 degrees about 55 million years ago, and this warming lasted for about 100,000 years.

Some climatologists explain this warming by methane discharges into the atmosphere. This methane hypothesis was reviewed by the specialists of the Obukhov Insititue of Atmospheric Physics, Russian Academy of Sciences, under the guidance of Academician Georgy Golitsyn. According to the researchers’ opinion, quick (in terms of geology) methane-based warming is possible in principle, although it requires considerable methane streams from the interior of the Earth.

Within the long history of the Earth, its climate has changed a lot of times. The orbit parameters changed, continents and oceans shifted on the planet, big asteroids fell down on the Earth and volcanoes began to erupt. In the last decade of the 20th century, scientific community started to discuss one more possibility for climatic changes, which are long-term in terms of human history and quick in terms of geological time scale. This is the so-called “methane catastrophe” – discharge of large quantity of methane from gas hydrates located in the interior of the Earth. As a result, the climate got warmer within 15-30,000 years, which noticeably changed the late Palaeocene world. However, many researchers assume that the reason for global warming was quick increase of carbonic acid gas concentration in the atmosphere. So, what is to blame: carbonic acid gas or methane?

In 1750 during the pre-industrial epoch, the terrestrial atmosphere contained approximately 1,85 Gt of methane. To explain the warming that occurred 55 million years ago, the methane concentration would have increased by over a hundred times as compared to pre-industrial levels, and the carbonic acid gas concentration by only six times. As there was a sufficient quantity of methane in the interior of the Earth, estimated at between 700 and 30,000 Gt, it is possible that between 1,000 and 2,000 Gt was discharged from the interior of the Earth, of which 400 Gt fell on the Arctic permafrost zone.

Due to the molecular mass difference, carbonic dioxide formation requires 2,75 times more carbon than formation of the same quantity of methane, and as methane is a stronger greenhouse gas than carbonic dioxide, its potential would be 21 times higher than a similar potential of carbonic acid gas. If different absorbent properties of greenhouse gases are taken into account, then greenhouse warming due to methane concentration would have required six times less carbon than the warming due to carbonic acid gas, and, accordingly, much smaller discharge of carbon from the planet interior would have been sufficient.

There are other arguments in favor of the “methane” hypothesis. As the methane concentration in the atmosphere increases, its stability also grows. Thus, in the pre-industrial epoch, the methane molecule lifespan in the atmosphere was 8,4 years, in contemporary conditions - about 10 years, but 55 million years ago, during massive gas discharges, it could exceed 40 years. Besides, in case of high concentration of greenhouse gases in the atmosphere, the water vapour concentration also grows, which increases the greenhouse effect. To achieve the same increase of surface temperature (taking into account the water vapour influence), twice lower methane content in the atmosphere (and less discharge from gas hydrates) would have been sufficient. According to the Russian researchers’ estimates, during the warming period, the annual methane stream into the atmosphere should have been 25 Gt, if the methane molecule lived for 10 years, and 6 Gt, if its lifespan was increased up to 40 years. (In the contemporary world, the major methane leakage from the interior of the Earth occurs owing to natural gas production and makes about 600 Mt per year, and the atmosphere contains 4,6 Gt of methane).

The above estimates demonstrate that quick (in terms of geology) methane-based warming is possible in principle, although it requires considerable methane discharges. Probably, volley methane discharges in the geological past could be the trigger to launch the “quick” warming process. According to the recent palaeontological data, the methane concentration growth normally passes ahead of the temperature growth. Such mechanism explains why some warmings in the history of the Earth had happened earlier than the carbonic acid gas concentration increased.

Nevertheless, the Russian researchers point out that detailed review of the greenhouse phenomenon at the Palaeocene/Eocene border has not been finished yet. It requires further investigation with involvement of geological, geochemical and paleoenvironmental records and contemporary climatic theory models.

Nadezda Markina | alfa
Further information:
http://www.informnauka.ru

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>