Cennomanian Fossil Polar Forest Found on Chatham Island

Large trees in their original living position, early flowering plants, seed cones and rare insects preserved in a rock formation were discovered by researchers in the Chatham Islands. The find reveals what is believed to be the first records of life close to the South Pole during the Cretaceous period, a time of extreme greenhouse conditions 145-65 million years ago.

Led by palaeontologist Associate Professor Jeffrey Stilwell and palaeobotanist Dr Chris Mays from Monash University's School of Geosciences, a research team including Professor David Cantrill from the Royal Botanic Gardens Melbourne made the discovery.

Associate Professor Stilwell said the fossils painted a picture of the formerly unknown life of the Cretaceous period when many southern continents including New Zealand and the Chatham Islands (Zealandia), Australia, Antarctica and South America were still mostly joined together as part of the southern landmass Gondwana.

"One hundred million years ago, the Earth was in the grip of a greenhouse effect – a planet of extreme heat with minimal ice (except in the high altitudes) and sea levels of up to 200 metres higher than today," Associate Professor Stilwell said.

"Rainforests inhabited by dinosaurs existed in sub-polar latitudes and polar ecosystems were adapted to long months of winter darkness and summer daylight.

"Never before have we had evidence about what life existed near the South Pole 90 to 100 million years, or the conditions that life on land experienced.

The discovery, 865 kilometres east of New Zealand, was made in one the most remote fossil locations known in the Southern Hemisphere while researchers were investigating a bone bed further north on Chatham Island and plant remains on nearby Pitt Island.

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Polar Methane Quantity Increasing

A rise in concentrations of a powerful greenhouse gas over the Arctic after a decade of stability is stirring worries about a possible thaw of vast stores trapped in permafrost, experts said.

Levels of methane in the atmosphere rose 0.6 percent in 2008, according to preliminary data from the Zeppelin station on a remote island in the Norwegian Arctic, after a similar 0.6 percent gain in 2007, Norwegian officials said.

The 2007 rise outpaced a global rise in methane of 0.34 percent to a new record high after levels had been stable for about a decade. World data for 2008 are not yet available.

"The biggest worry is that there are emissions from the permafrost, and also from wetlands in the northern region," said Catherine Lund Myhre, senior scientist at the Norwegian Institute for Air Research.

A thaw of permafrost, such as in Siberia or Canada, could release vast amounts of trapped greenhouse gases and in turn accelerate global warming. "There may be several causes for the rise. Currently it's not solved," she told Reuters.

Methane is the second most important greenhouse gas behind carbon dioxide, accounting for about 18 percent of the heat-trapping greenhouse effect from human activities that might trigger more heatwaves, floods or rising seas.

Methane is emitted from natural sources -- such as from decaying plants in swamps or by termites -- and by human use of fossil fuels, rice paddies, landfills and from the digestive tracts of animals such as cows and sheep.

Paul Fraser, a chief research scientist at the Australian Commonwealth Scientific and Research Organization, said wetlands, both in the tropics and in the north, seemed a likely source of extra methane after a drier period.

Very quick comment: I wonder if this - methane accumulation at the poles, not unlike what happens with CFCs - is what warms the poles so much during Green House Climates (most recently the Eocene).