MOffett Feild CA (SPX) Sep 10, 2009
When planet Earth was just cooling down from its fiery creation, the sun was faint and young. So faint that it should not have been able to keep the oceans of Earth from freezing. But fortunately for the creation of life, water was kept liquid on our young planet.
For years scientists have debated what could have kept Earth warm enough to prevent the oceans from freezing solid. Now a team of researchers from Tokyo Institute of Technology and University of Copenhagen's Department of Chemistry have coaxed an explanation out of ancient rocks, as reported in the journal PNAS

A perfect greenhouse gas
"The young sun was approximately 30 percent weaker than it is now, and the only way to prevent Earth from turning into a massive snowball was a healthy helping of greenhouse gas," Associate Professor Matthew S. Johnson of the Department of Chemistry explains. He has found the most likely candidate for an Archean atmospheric blanket is carbonyl sulphide, a product of the sulphur disgorged during millennia of volcanic activity.

"Carbonyl sulphide is and was the perfect greenhouse gas. Much better than carbon dioxide. We estimate that a blanket of carbonyl sulphide would have provided about 30 percent extra energy to the surface of the planet, and that would have compensated for what was lacking from the sun," says Johnson.

Strange distribution
To discover what could have helped the faint young sun warm early Earth, Johnson and his colleagues in Tokyo examined the ratio of sulphur isotopes in ancient rocks.They saw a strange signal: A mix of isotopes that couldn't have come from geological processes.

"There is really no process in the rocky mantle of Earth that would explain this distribution of isotopes," says Johnson. "You would need something happening in the atmosphere."

Painstaking experimentation helped the researchers find a likely atmospheric process. By irradiating sulphur dioxide with different wavelengths of sunlight, they observed that sunlight passing through carbonyl sulphide gave them the wavelengths that produced the weird isotope mix.

"Shielding by carbonyl sulphide is really a pretty obvious candidate once you think about it, but until we looked, everyone had missed it," says Johnson. "What we found is really an archaic analogue to the current ozone layer, a layer that protects us from ultraviolet radiation. But unlike ozone, carbonyl sulphide would also have kept the planet warm.

The only problem is, it didn't stay warm."

Life caused Ice Age
As life emerged on Earth, it produced increasing amounts of oxygen. With an increasingly oxidizing atmosphere, the sulphur emitted by volcanoes was no longer converted to carbonyl sulphide. Instead it was converted to sulphate aerosols, which are powerful climate coolants.

Johnson and his co-workers created a computer model of the ancient atmosphere. In conjunction with laboratory experiments, the model suggests that the fall in carbonyl sulphide and rise of sulphate aerosols taken together would have been responsible for creating Snowball Earth, the planet-wide Ice Age hypothesised to have taken place near the end of the Archean era 2.5 billion years ago.

The implications to Johnson are alarming. "Our research indicates that the distribution and composition of atmospheric gasses swung the planet from a state of life-supporting warmth to a planet-wide Ice Age spanning millions of years. I can think of no better reason to be extremely cautious about the amounts of greenhouse gasses we are currently emitting to the atmosphere."
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Durham, UK (SPX) Mar 10, 2009
Climate change is already having a detectable impact on birds across Europe, says a Durham University and RSPB-led scientific team publishing their findings to create the world's first indicator of the climate change impacts on wildlife at a continental scale.
Published in the journal PLoS ONE, Durham University scientists working with the Royal Society for the Protection of Birds have shown a strong link between recent population changes of individual species and their projected future range changes, associated with climate change, among a number of widespread and common European birds, including the goldfinch and the lesser spotted woodpecker.

By pulling together Europe-wide monitoring data, the team has compiled an indicator showing how climate change is affecting wildlife across Europe. The European Union has adopted the indicator as an official measure of the impacts of climate change on the continent's wildlife; the first indicator of its kind.

The paper and the indicator were produced by a team of scientists from the RSPB, Durham University, Cambridge University, the European Bird Census Council, the Museum National d'Histoire Naturelle, the Czech Society for Ornithology, and Statistics Netherlands.

European population data for birds was compiled by The Pan-European Common Bird Monitoring Scheme (PECBMS), a partnership involving the European Bird Census Council (EBCC), the RSPB, BirdLife International, and Statistics Netherlands funded by the RSPB and the European Commission

Dr Stephen Willis, of Durham University, said: "The impact of climatic changes, both positive and negative, can now be summarised in a single indicator which we've called the Climatic Impact Indicator. A period of stable annual average temperatures in Europe ended in the early 1980s, and this new Indicator shows that climate change is affecting many species but in different ways. Climate change is having an adverse effect on many birds, though some species are actually benefiting from the recent changes.

"Our indicator is the biodiversity equivalent of the FTSE index, only instead of summarising the changing fortunes of businesses, it summarises how biodiversity is changing due to climate change. Unlike the FTSE, which is currently at a six year low, the climate change index has been increasing each year since the mid-80s, indicating that climate is having an increasing impact on biodiversity.

"Those birds we predict should fare well under climate change have been increasing since the mid-80s, and those we predict should do badly have declined over the same period. The worry is that the declining group actually consists of 75 per cent of the species we studied."

The Climate Change Indicator combines two independent strands of work; bioclimate envelope-modelling and observed populations trends in European birds, derived from the Pan-European Common Bird Monitoring Scheme.

When a bird's population changes in line with the projection, the indicator goes up. Species whose observed trend does not fit the projection cause the indicator to decline.

The RSPB's Dr Richard Gregory said: "We hear a lot about climate change, but our paper shows that its effects are being felt right now. The results show the number of species being badly affected outnumbers the species that might benefit by three to one. Although we have only had a very small actual rise in global average temperature, it is staggering to realise how much change we are noticing in wildlife populations. If we don't take our foot off the gas now, our indicator shows there will be many much worse effects to come. We must keep global temperature rise below the two degree ceiling; anything above this will create global havoc."

The research shows that a number of species are projected to increase the populations across Europe. Of the 122 species that were surveyed, the top ten increasing species (in order) are: Sardinian warbler (P); subalpine warbler (P); bee-eater (P); cirl bunting (B); Cetti's warbler (B); hoopoe (P); golden oriole (B); goldfinch (B); great reed warbler (P); and collared dove (B).

Species in this list marked with a (B) already breed regularly in the UK. Species marked with a (P) are potential colonists to the UK if they continue to respond to climatic warming in the way the models predict, and in the absence of other barriers (such as the ability to disperse and the availability of suitable habitat).

Of those species surveyed the worst performers across Europe (in order) are: snipe (B); meadow pipit (B); brambling (occasional B); willow tit (B); lapwing (B); thrush nightingale; wood warbler (B); nutcracker; northern wheatear (B); and lesser spotted woodpecker (B).

Of the 122 species included (out of 526 species which nest in Europe), 30 are projected to increase their range; while the remaining 92 species are anticipated to decrease their range.

Dr Gregory added: "This new work emphasises again the role played by skilled amateur birdwatchers right across Europe in advancing our understanding of the environment and the growing threat posed by climate change."

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