October 2006


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With less than two weeks until the November elections mailboxes are stuffed with oversized full color flyers and the airwaves are a near constant drone of campaign rhetoric. Politicos have latched onto Global Warming this season by either holding up their voting record or fingerpointing to their opponents lack of action.

Is this the way to solve anything?

Visit tinysteps.com a website that is a reader generated list of small simple things anyone can do that multiplied by tens of millions on a daily basis can make a difference. Please add your suggestion to the growing list. Let’s all own Global Warming.

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  And what about Thomas Gold?

For immediate release: October 20, 2006
Media contact: Chad Boutin, (609) 258-5729, cboutin@princeton.edu

Two miles underground, strange bacteria are found thriving

A Princeton-led research group has discovered an isolated community of bacteria nearly two miles underground that derives all of its energy from the decay of radioactive rocks rather than from sunlight. According to members of the team, the finding suggests life might exist in similarly extreme conditions even on other worlds.

The self-sustaining bacterial community, which thrives in nutrient-rich groundwater found near a South African gold mine, has been isolated from the Earth’s surface for several million years. It represents the first group of microbes known to depend exclusively on geologically produced hydrogen and sulfur compounds for nourishment. The extreme conditions under which the bacteria live bear a resemblance to those of early Earth, potentially offering insights into the nature of organisms that lived long before our planet had an oxygen atmosphere.

The scientists, who hail from nine collaborating institutions, had to burrow 2.8 kilometers beneath our world’s surface to find these unusual microbes, leading the scientists to their speculations that life could exist in similar circumstances elsewhere in the solar system.

“What really gets my juices flowing is the possibility of life below the surface of Mars,” said Tullis Onstott, a Princeton University professor of geosciences and leader of the research team. “These bacteria have been cut off from the surface of the Earth for many millions of years, but have thrived in conditions most organisms would consider to be inhospitable to life. Could these bacterial communities sustain themselves no matter what happened on the surface? If so, it raises the possibility that organisms could survive even on planets whose surfaces have long since become lifeless.”

Onstott’s team published its results in the Oct. 20 issue of the journal Science. The research group includes first author Li-Hung Lin, who performed many of the analyses as a doctoral student at Princeton and then as a postdoctoral researcher at the Carnegie Institution.

“These bacteria are truly unique, in the purest sense of the word,” said Lin, now at National Taiwan University. “We know how isolated the bacteria have been because analyses of the water that they live in showed that it’s very old and hasn’t been diluted by surface water. In addition, we found that the hydrocarbons in the environment did not come from living organisms, as is usual, and that the source of the hydrogen needed for their respiration comes from the decomposition of water by radioactive decay of uranium, thorium and potassium.”
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Because the groundwater the team sampled to find the bacteria comes from several different sources, it remains difficult to determine specifically how long the bacteria have been isolated. The team estimates the time frame to be somewhere between three and 25 million years, implying that living things are even more adaptable than once thought.

“We know surprisingly little about the origin, evolution and limits for life on Earth,” said biogeochemist Lisa Pratt, who led Indiana University Bloomington’s contribution to the project. “Scientists are just beginning to study the diverse organisms living in the deepest parts of the ocean, and the rocky crust on Earth is virtually unexplored at depths more than half a kilometer below the surface. The organisms we describe in this paper live in a completely different world than the one we know at the surface.”

That subterranean world, Onstott said, is a lightless pool of hot, pressurized salt water that stinks of sulfur and noxious gases humans would find unbreathable. But the newly discovered bacteria, which are distantly related to the Firmicutes division of microbes that exist near undersea hydrothermal vents, flourish there.

“The radiation allows for the production of lots of sulfur compounds that these bacteria can use as a high-energy source of food,” Onstott said. “For them, it’s like eating potato chips.”

But the arrival of the research team brought one substance into the underground world that, though vital to human survival, proved fatal to the microbes — air from the surface.

“These critters seems to have a real problem with being exposed to oxygen,” Onstott said. “We can’t seem to keep them alive after we sample them. But because this environment is so much like the early Earth, it gives us a handle on what kind of creatures might have existed before we had an oxygen atmosphere.”

Onstott said that many hundreds of millions of years ago, some of the first bacteria on the planet may have thrived in similar conditions, and that the newly discovered microbes could shed light on research into the origins of life on Earth.

“These bacteria are probably close to the base of the tree for the bacterial domain of life,” he said. “They might be genealogically quite ancient. To find out, we will need to compare them to other organisms such as Firmicutes and other such heat-loving creatures from deep sea vents or hot springs.”

The research team is building a small laboratory 3.8 kilometers beneath the surface in the Witwatersrand region of South Africa to conduct further study of the newly discovered ecosystem, said Onstott, who hopes the findings will be of use when future space probes are sent to seek life on other planets. 

“A big question for me is, how do these creatures sustain themselves?” Onstott said. “Has this one strain of bacteria evolved to possess all the characteristics it needs to survive on its own, or are they working with other species of bacteria? I’m sure they will have more surprises for us, and they may show us one day how and where to look for microbes elsewhere.”

Other authors of this work include Johanna Lipmann-Pipke of GeoForschungsZentrum, Potsdam, Germany; Erik Boice of Indiana University; Barbara Sherwood Lollar of the University of Toronto; Eoin L. Brodie, Terry C. Hazen, Gary L. Andersen and Todd Z. DeSantis of Lawrence Berkeley National Laboratory, Berkeley, Calif.; Duane P. Moser of the Desert Research Institute, Las Vegas; and Dave Kershaw of the Mponeng Mine, Anglo Gold, Johannesburg, South Africa.

Pratt and Onstott have collaborated for years as part of the Indiana-Princeton-Tennessee Astrobiology Institute (IPTAI), a NASA-funded research center focused on designing instruments and probes for life detection in rocks and deep groundwater on Earth during planning for subsurface exploration of Mars. IPTAI’s recommendations to NASA will draw on findings discussed in the Science report.

This work was also supported by grants from the National Science Foundation, the U.S. Department of Energy, the National Science Council of Taiwan, the Natural Sciences and Engineering Research Council of Canada, Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) and the Killam Fellowships Program.

More information about the discovery can be found at http://newsinfo.iu.edu/news/page/normal/4229.html and http://www.carnegieinstitution.org/news_releases/news_2006_1019.html

Abstract

Long-Term Sustainability of a High-Energy, Low-Diversity Crustal Biome

By Li-Hung Lin, Pei-Ling Wang, Douglas Rumble, Johanna Lippmann-Pipke, Erik Boice, Lisa M. Pratt, Barbara Sherwood Lollar, Eoin L. Brodie, Terry C. Hazen, Gary L. Andersen, Todd Z. DeSantis, Duane P. Moser, Dave Kershaw, and T. C. Onstott

Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities for millions of years with no apparent reliance on photosynthetically derived substrates.


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Expect a Warmer, Wetter World this Century, Computer Models Agree

October 19, 2006

BOULDER—Recent episodes of deadly heat in the United States and Europe, long dry spells across the U.S. West, and heavy bursts of rain and snow across much of North America and Eurasia hint at longer-term changes to come, according to a new study based on several of the world’s most advanced climate models. Much of the world will face an enhanced risk of heat waves, intense precipitation, and other weather extremes, conclude scientists from the National Center for Atmospheric Research (NCAR), Texas Tech University, and Australia’s Bureau of Meteorology Research Centre. The new study, “Going to the Extremes,” will appear in the December issue of the journal Climatic Change.

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Many previous studies have looked at how average temperature or rainfall might change in the next century as greenhouse gases increase. However, the new research looks more specifically at how weather extremes could change.

“It’s the extremes, not the averages, that cause the most damage to society and to many ecosystems,” says NCAR scientist Claudia Tebaldi, lead author for the report. “We now have the first model-based consensus on how the risk of dangerous heat waves, intense rains, and other kinds of extreme weather will change in the next century.”

The study is one of the first analyses to draw on extensive and sophisticated computer modeling recently carried out for the Intergovernmental Panel on Climate Change. The IPCC’s next assessment report will be released early in 2007.

Tebaldi and colleagues based their work on simulations from nine different climate models for the periods 1980–1999 and 2080–2099. The simulations were created on supercomputers at research centers in France, Japan, Russia, and the United States. Each model simulated the 2080-2099 interval three times, varying the extent to which greenhouse gases accumulate in the atmosphere. These three scenarios were used to account for uncertainty over how fast society may act to reduce emissions of carbon dioxide and other greenhouse gases over coming decades.

From the model output, the scientists computed 10 different indices of climate extremes, with 5 related to temperature and 5 to moisture. For instance, a frost days index measures how many days per year temperatures dip below 32 degrees Fahrenheit, while a dry days index measures the length of each year’s longest consecutive string of days without rain or snow. Because the impact of a given index can be stronger in one climatic zone than another, the authors expressed the results in terms of statistical significance at each location.

For all three greenhouse-gas scenarios, the models agree that by 2080-2099:

  • The number of extremely warm nights and the length of heat waves will increase significantly over nearly all land areas across the globe. During heat waves, very warm nights are often associated with fatalities because people and buildings have less chance to cool down overnight.
  • ct-ww-rain.jpgMost areas above about 40 degrees north will see a significant jump in the number of days with heavy precipitation (days with more than 0.40 inches). This includes the northern tier of U.S. states, Canada, and most of Europe.
  • Dry spells could lengthen significantly across the western United States, southern Europe, eastern Brazil, and several other areas. Dry spells are one of several factors in producing and intensifying droughts.
  • The average growing season could increase significantly across most of North America and Eurasia.

Most of these trends are significantly weaker for the lowest-emission scenario than for the moderate and high-emission scenarios. Thus, the authors add, lowering the output of greenhouse gases over the next century should reduce the risk that the most severe changes will occur.

The research was supported by the National Science Foundation, which is NCAR’s primary sponsor, as well as by the U.S. Department of Energy and Environmental Protection Agency.

About the article

Title: “Going to the Extremes: An intercomparison of model-simulated historical and future changes in extreme events”

Author: Claudia Tebaldi, Katharine Hayhoe, Julie M. Arblaster, and Gerald A. Meehl

Publication: Climatic Change, December 2006

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Image courtesy of NASA

for article click here

 

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Larsen ice shelf

Photo courtesy of NASA

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Scientic American

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