Greenhouse gases could have caused an ice age, claim scientists

Rocks show life began 1bn years earlier than first thought
The Guardian
Saturday August 14, 1999
[orig: www.newsunlimited.co.uk/uk_news/story/0,3604,73745,00.html]
Scientists studying Australian rocks have found evidence that primitive forms of life existed 2.7bn years ago - a billion years earlier than had been previously shown... The finding pushes back evidence of life to the Archean era, the period from the beginning of earth to about 2.5bn years ago... Most rocks as old as the ones studied have undergone a process called metamorphism, an intense geological heating that changes them and which scientists believed would destroy any organic compounds they contained. But the shales studied by this team were well-preserved and still contained the biological chemicals. The researchers found evidence of organic compounds called lipids in the sedimentary rocks located more than 2,100ft deep in north-western Australia's Roy Hill Shale and Marra Mamba Formations. The rocks formed a seabed 2.6 bn to 2.7 bn years ago... Because of their complexity, eukaryotes were thought to have developed relatively late in earth's history. This discovery pushes the date for their appearance back to the earliest part of geological time.
Early life theory takes a biff
May 24, 2002
Moreover, the carbon isotopic basis used for interpreting its organic origin is questionable, the authors say. The authors demonstrate that much of the fine layering in the banded rocks, interpreted as a typical BIF (Banded Iron Formation) sedimentary structure, was in fact formed as a result of metamorphic processes.

A chemical study of the rocks also points away from a BIF origin for the banded rock. Analyses of green bands show that their composition is very similar to komatiite, a type of basalt. If this is correct there is little chance that the preserved graphite represents past life.

Recent studies of hydrothermal vents on mid-ocean ridges have also shown that basalt-like rocks can interact with water to form carbon compounds by non-biological processes, leaving an isotopic signature similar to that of metabolic function. While it is possible life existed on Earth when the rocks on Akilia formed, direct evidence for life older than approximately 3.8 billion years ago is still lacking.
Paleoproterozoic snowball Earth (pdf)
Joseph L. Kirschvink et al
This snowball model predicts that postglacial, greenhouse-induced warming would lead to the deposition of banded iron formations and cap carbonates. Although global glaciation would have drastically curtailed biological productivity, melting of the oceanic ice would also have induced a cyanobacterial bloom, leading to an oxygen spike in the euphotic zone and to the oxidative precipitation of iron and manganese... Kirschvink noted that the extreme geochemical environments predicted by a snowball Earth model explain the Neo-proterozoic banded iron formations (BIFs).

Please note that this was 630 MILLION year ago, not 630 THOUSAND, or 63 MILLION years ago. Thus the continents were arranged completely differently, there was no Pacific Current or Gulf Stream, and it was ten times before the dinosaurs were wiped out. See my Comment 78(?). I may be off by a number or two, senior moments. Nevertheless, there is something to be said for simplicity in explanations. I like the one that suggested that with vulcanism, CO2 built up, eventually warming took place and rain began again, melting the ice.

Oddly enough, I've got nothin' on the hard drives about one of that date. I've got earlier stuff, but the closest is 1.2 billion years ago. :'o

Earth's most ancient rocks, with an age of 4.28 billion years, have been found on the shore of Hudson Bay, Canada. Writing in Science journal, a team reports finding that a sample of Nuvvuagittuq greenstone is 250 million years older than any rocks known. It may even hold evidence of activity by ancient life forms. If so, it would be the earliest evidence of life on Earth - but co-author Don Francis cautioned that this had not been established... "Now we have pushed the Earth's crust back by hundreds of millions of years. That's why everyone is so excited." ... the majority of our planet's early crust has already been mashed and recycled into Earth's interior several times over... Before this study, the oldest whole rocks were from a 4.03 billion-year-old body known as the Acasta Gneiss, in Canada's Northwest Territories. The only things known to be older are mineral grains called zircons from Western Australia, which date back 4.36 billion years... The material displays a banded iron formation - fine ribbon-like bands of alternating magnetite and quartz. This feature is typical of rock precipitated in deep sea hydrothermal vents - which have been touted as potential habitats for early life on Earth. *

Well, see, now, I checked a little more, and...

Sudden Increase In Asteroid Impacts May Have Fueled Life
by Robert Roy Britt
March 10, 2000
In a finding that may impact everything from how life evolves to whether our sun has a companion star, researchers have found that the moon underwent a flurry of collisions from asteroids and comets between 400 million and 600 million years ago. The active period, which may still be going on, most likely affected Earth as well since both bodies are in roughly the same spot in the solar system, researchers said. The beginning of the busy stretch coincided with a rapid proliferation of life on Earth, suggesting a possible connection... The data, reported in the March 10 issue of the journal Science, show that the impact crater creation rate -- which was high 3.5 billion years ago when large space rocks were being cleaned up by gravity in the fledgling solar system -- had dropped steadily until an unexpected rise 400 million to 600 million years ago... The sudden increase coincides with the "Cambrian explosion," a period in which life on Earth took off with a dramatic burst in the number and diversity of species.

Thanks for the ping!

I hope we aren’t going to start gauging researchers on their level of stupidity or choice of beer...this would take out a huge segment of our society and basically dump them back on Wal-Mart, Shoney’s Big Boy, and the US Army. We need to keep these researchers busy on something...or they might screw up America bigtime.

Hi to Neverdem and the others,

I originated the press release which the Telegraph unfortunately completely garbled presumably in order to make a sensational headline. We said that the Earth remained cold in spite of [the build-up of] high greenhouse gases! I’m sure you folks know that it is difficult to trust media sources. It seems like playing with fire, but it is part of our duty as scientists to communicate and run the risk of mis-reporting. Anyway, if readers are interested in reading about what we actually did, you can look it up at:
http://www.gees.bham.ac.uk/staff/fairchildresearchglacial.shtml

While pollution in the air is thought to trap the sun's heat in the atmosphere, causing the planet to heat up, this new research suggests it could also have the opposite effect reflecting rays back into space.

These 'scientist' have no clue. Now they're studying 630 million year old limestone rock and drawing all sorts of conclusions.

They need to stop trying to concoct scenarios that blame it all on man, and start really studying all data available about that big yellow ball in the sky, and how variations in its activity just might have some impact on temperatures on earth.

eukaryotes were thought to have developed relatively late in earth's history.

The prokaryotes weren't doing a good job of converting the Earth's atmosphere. Nature evolved a better model that had an internal engine.

I thought the patent on R-12 had run out?

Which is why they were searching for a way to make more profit. They had lost their income from the R-12.