Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Planetary ‘runaway greenhouse’ more easily triggered, research shows

31.07.2013
It might be easier than previously thought for a planet to overheat into the scorchingly uninhabitable “runaway greenhouse” stage, according to new research by astronomers at the University of Washington and the University of Victoria published July 28 in the journal Nature Geoscience.

In the runaway greenhouse stage, a planet absorbs more solar energy than it can give off to retain equilibrium. As a result, the world overheats, boiling its oceans and filling its atmosphere with steam, which leaves the planet glowing-hot and forever uninhabitable, as Venus is now.

One estimate of the inner edge of a star’s “habitable zone” is where the runaway greenhouse process begins. The habitable zone is that ring of space around a star that’s just right for water to remain in liquid form on an orbiting rocky planet’s surface, thus giving life a chance.

Revisiting this classic planetary science scenario with new computer modeling, the astronomers found a lower thermal radiation threshold for the runaway greenhouse process, meaning that stage may be easier to initiate than had been previously thought.

“The habitable zone becomes much narrower, in the sense that you can no longer get as close to the star as we thought before going into a runaway greenhouse,” said Tyler Robinson, a UW astronomy postdoctoral researcher and second author on the paper. The lead author is Colin Goldblatt of the University of Victoria.

Though further research is called for, the findings could lead to a recalibration of where the habitable zone begins and ends, with some planets having their candidacy as possible habitable worlds revoked.

“These worlds on the very edge got ‘pushed in,’ from our perspective — they are now beyond the runaway greenhouse threshold,” Robinson said.

Subsequent research, the astronomers say, is needed in part because their computer modeling was done in a “single-column, clear-sky model,” or a one-dimensional measure averaged around a planetary sphere that does not account for the atmospheric effect of clouds.

The findings apply to planet Earth as well. As the sun increases in brightness over time, Earth, too, will move into the runaway greenhouse stage — but not for a billion and a half years or so. Still, it inspired the astronomers to write, “As the solar constant increases with time, Earth’s future is analogous to Venus’s past.”

Other co-authors are Kevin J. Zahnle of the NASA Ames Research Center in Moffett Field, Calif.; and David Crisp of the Jet Propulsion Laboratory in Pasadena, Calif.

For more information, contact Robinson at 520-907-8369, or robinson@astro.washington.edu; or Goldblatt at 250-721-7641 or czg@uvic.ca.

Peter Kelley | EurekAlert!
Further information:
http://www.uw.edu

More articles from Earth Sciences:

nachricht Clear as mud: Desiccation cracks help reveal the shape of water on Mars
20.04.2018 | Geological Society of America

nachricht Hurricane Harvey: Dutch-Texan research shows most fatalities occurred outside flood zones
19.04.2018 | European Geosciences Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>