Why Early Earth Didn't Freeze Over Still a Mystery

Global warming gases cannot explain why Earth was not frozen billions of years ago when the sun was cooler, researchers say.

In the Archean Eon about 2.5 billion to 4 billion years ago, before the first advanced life appeared on the planet, the sun was only about 70 percent as bright as it is today. This means the amount of heat felt on Earth was much less, and Earth's surface should have been frozen.

However, ancient rocks at Isua near the southwest coast of Greenland indicate liquid water and even life was present on Earth about 3.8 billion years ago. "So Earth's climate had to be somewhere between the freezing point and boiling point of water, and probably pretty close to the temperature we have today, which sustains life," said researcher Emily Pope, an isotope geochemist at the Natural History Museum of Denmark in Copenhagen.

The contradiction between the cold Earth that apparently should have existed and the temperate Earth that apparently did exist is known as the "faint young sun paradox." Until now, the most popular explanation for this enigma was that there was a higher concentration of "greenhouse gases" such as carbon dioxide in the atmosphere than today. These gases absorb heat from the sun, helping warm the planet.

"Just like the average temperature of Earth is getting higher today because there are more greenhouse gases than there were before the Industrial Revolution, or even before the invention of agriculture, the presence of high concentrations of carbon dioxide and methane should have kept the early Earth warm," Pope said. [Early Earth Was Purple]

For greenhouse gases to explain the faint young sun paradox, their concentrations would need to have been extremely high, hundreds to thousands of times as much as today.

"If levels of carbon dioxide were that high, they would be recorded in ancient soils and sediments in the rock record," Pope said. "If levels of methane were that high, they would actually form a kind of organic haze in the atmosphere that blocks the sun's rays and would counteract its properties as a greenhouse gas."

Now scientists analyzing relatively pristine 3.8-billion-year-old rocks from Isua find no evidence that greenhouse gas levels were high enough to explain the faint young sun paradox, further deepening the mystery, Pope told LiveScience.

Specifically, researchers looked at serpentine mineral deposits, which form when ancient seawater interacts with deep ocean crust (the outer layer of Earth). These deposits record details of the water such as the hydrogen and oxygen isotope ratios found within, which rely in part on ocean size. Isotopes are atoms of the same element, like hydrogen, with differing numbers of neutrons. Light hydrogen isotopes are more likely to be found in the air and escape into space than heavier ones; the smaller the oceans, the more their waters will have slightly lower concentrations of light isotopes.

The rocks suggest that the oceans were up to 26 percent larger in the past. These shrunk over time to present-day volumes — seawater became trapped in newly formed continental rocks, and hydrogen that is one of the key ingredients of water instead escaped to outer space.

The rate of hydrogen loss to space is linked to atmospheric levels of methane and carbon dioxide; both these greenhouse gases can interact with hydrogen and other gases such as oxygen in complex ways. The hydrogen loss rate the researchers estimated based on these findings suggests that concentrations of these greenhouse gases were nowhere near high enough to reconcile the faint young sun paradox. [Stunning Images of the Sun]

"We have new concrete data that characterizes the early oceans," Pope said. "This will hugely help our ability to put realistic constraints on our models of how Earth's oceans and atmosphere first evolved."

An alternative explanation for the faint young sun paradox is that early in Earth history, there were fewer continents because a number had not formed yet; less land mass would have meant less cloud cover, because there weren't biologically generated particles such as pollen and spores that could behave as seeds around which the clouds could form. 

"The result was that the planet, covered mostly by oceans, was darker, and like an asphalt road on a hot day, could absorb a lot more heat, enough to keep the Earth clement," Pope told LiveScience.

The scientists detailed their findings online March 5 in the journal Proceedings of the National Academy of Sciences.

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Early fall storm hammers Calif raisins in fields (AP)

FRESNO, Calif. – A storm dumped more than an inch of rain on parts of California's agricultural heartland in less than five hours, flooding streets, uprooting trees and soaking a bumper crop of raisins drying in vineyards.

The storm hit Tuesday in Northern California, then swept through the central portions before bringing rainfall to Southern California by midmorning on Wednesday.

A live web cam at China Peak in the central Sierra Nevada showed snow accumulation on the slopes. Squaw Valley USA reported eight inches of new snow overnight, with up to nine more predicted by Thursday. The snow forced the closing of the 9,300-foot Tioga Pass through Yosemite National Park.

"It is an early winter storm. It is not unheard of to have one this early," said Cindy Bean, a meteorologist with the National Weather Service in Hanford.

The storm was especially painful to California's agriculture industry.

Leading up to the deluge, alfalfa growers worked to bale late cuttings, and cotton growers were scrambling to harvest before the storm hit. Rain can soak bolls and cause the cotton to fall out, making it unusable.

Wine grape growers, who are in the midst of harvest, generally did not expect the rain to be as much of a problem as it would have been if it had come earlier, when mold can develop. In Napa County, only cabernet sauvignon remains in the fields, and its thick skin serves as a protection, growers said. On the Central Coast, growers in the midst of harvest said the rain would serve to wash the dust from the grapes, but likely would not cause damage.

But their colleagues in the raisin industry were hammered. An unseasonably cool spring delayed the peak harvest, for some even past even the Sept. 25 deadline they needed to qualify for crop insurance.

Growers say nearly half of the raisin crop was soaked as it dried in the fields.

"Overall, we think 40 to 50 percent of the raisin crop has been exposed," said Eric Cisneros of Fresno Cooperative Raisin Growers. "If we get a little bit of wind and sun, it could help. But with the rain comes mold, so it all depends on what stage of drying they are in."

California produces 360,000 tons of raisins annually, or about 40 percent of the world total.

The rain in the Central Valley turned to snow when it reached the Sierra Nevada, where chains were required at higher elevations.

"It's a storm similar to early December, but we just got it in early October," said Johnnie Powell, a National Weather Service forecaster in Sacramento.

No major damage was reported. Temperatures were expected to return to normal by the Columbus Day holiday weekend.

A storm warning remains in effect until late Wednesday for elevations above 6,000 feet. In the Central Valley and foothills, more showers and a chance of thunderstorms were expected.

"First and foremost, we want people to slow down," California Highway Patrol spokesman Adrian Quintero said.

Pacific Gas & Electric had nearly 2,200 customers without power in Amador, El Dorado, Nevada, Placer, San Joaquin and Yolo counties.

"Cars into utility poles on slick roads, that sort of thing," said PG&E spokesman Paul Moreno. "We're looking to get almost everyone back on by early afternoon."

The Sacramento Municipal Utility District, which provides electricity to Sacramento and part of Placer County, had outages affecting 1,100 customers when trees and branches collapsed onto power lines or blew fuses overnight.

In Southern California, the Los Angeles Fire Department had sandbags available for anyone concerned about flooding.

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Associated Press writers Sheila V Kumar in Sacramento, Brooke Donald in San Jose and Don Thompson in Sacramento contributed to this report.

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Japan's new PM suffers early blow as minister quits (Reuters)

TOKYO (Reuters) – Japanese Prime Minister Yoshihiko Noda's new government suffered a blow on Saturday after just eight days in office when the trade minister resigned over gaffes on the sensitive topic of radiation from the tsunami-hit Fukushima plant.

The resignation of Trade Minister Yoshio Hachiro, who handles the energy portfolio, will give opposition parties ammunition for attack as Noda strives to end the radiation crisis at the Fukushima plant while tackling a plethora of challenges from rebuilding after the March earthquake and tsunami to curbing huge public debt.

Hachiro submitted his resignation to Noda after reports that he joked with a reporter about radiation from the tsunami-crippled Fukushima nuclear plant, Jiji news agency and other domestic media reported. It was his second remark seen as offensive to victims of the worst nuclear accident in 25 years.

Japanese media said Hachiro had attempted to rub up against a reporter saying "I'll give you radiation" after visiting the Fukushima plant on Thursday.

Opposition party leaders criticised the remark and said that they would press Noda himself over his responsibility for appointing Hachiro, NHK public TV reported.

Hachiro had already been rebuked by Noda and apologised on Friday for calling the deserted area near the plant a "town of death," a comment seen as offensive to disaster victims.

Noda, who took over as Japan's sixth prime minister in five years after predecessor Naoto Kan resigned, will face harsh questioning over his appointment of Hachiro and other novice ministers in a session of parliament expected to begin next week. Defense Minister Yasuo Ichikawa has already come under attack for calling himself an "amateur" in security matters.

Noda, who won a bruising battle to become head of the ruling Democratic Party of Japan, has emphasized the need to restore fractured party unity in his appointments, raising concerns that he had done so at the expense of expertise.

"There was already great mistrust of his personnel appointments," said independent commentator Atsuo Ito.

Noda's quick decision to sacrifice Hachiro would probably help dampen public criticism, but a drop in his voter support could make it harder to obtain help from opposition parties to pass bills in the divided parliament, where they control the upper house and can block legislation, Ito added.

(Editing by Raju Gopalakrishnan)

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Early Footage from Joplin Tornado Documentary Moving, Oscar-Worthy (ContributorNetwork)

COMMENTARY | The first seven minutes of a documentary about the Joplin tornado are available on the Missouri Press Association's YouTube page. Shortly after the tornado struck, a team of three filmmakers interviewed staff from the Joplin Globe, who told their stories of the tornado as they saw it.

Reporters must be impartial in and of themselves. But this documentary is a revealing look about how a media outlet deals with a disaster in its town.

The documentary starts simply enough. A Sunday newspaper proclaims the Joplin High School graduation and the screen has quotes from graduates. A fan oscillates in the background and begins blowing the newspaper, symbolic of the EF5 tornado that was about to tear Joplin asunder.

Quotes from the graduates are hauntingly wrought with foreshadowing. One said, "Cherish your memories. The ride of your life is set to begin." Another stated, "Today is that something big."

An hour later, the graduates found out exactly how much those words would actually mean. An event that would forever define their lives happened right after the culmination of their hard work was celebrated.

If the preview is any indication, this documentary will win several awards. I couldn't help but cry through half of it.

One of the Globe's staffers died in the tornado. A quarter of the paper's employees were left homeless. Yet somehow, the coverage never stopped. People from outside the area were able to use the media outlet as a viable source for firsthand accounts of the tornado and its aftermath.

One reporter's first day on the job was supposed to be May 23. Josh Letner's work started about 12 hours earlier. Instead of covering town meetings or animal shelters, the young man started his journalism career with one of the biggest events to happen in the United States this year.

It's just Joplin. It's just a small town. Yet no matter how many times I read stories about the tornado and residents picking up the pieces, I can't help but feel something. This is my home state. My sister in-law and her family live south of town.

This story hits home. If your heart doesn't go out to the people in the film, you simply aren't human. Just like any picture or description of the tornado and its aftermath, these pictures won't do the event justice. However, it's the closest thing I've seen so far that makes the story as real as possible.

Titled "Tornado: Through the Eyes of the Joplin Globe," Orr Street Productions plans on having the final product out in early 2012, reports Riverfront Times. The production team has produced nationally known commercials and video.

The film should at least be nominated for an Academy Award from what I've already seen.

William Browning, a lifelong Missouri resident, writes about local and state issues for the Yahoo! Contributor Network. Born in St. Louis, Browning earned his bachelor's degree in English from the University of Missouri. He currently resides in Branson.

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