Hard Core Ice Record
Perhaps one of the best ways to predict the future is to study the past in the frozen ice of our polar ice caps. Many years ago, the French and the Russians studied the ice pack in Vladivostok and found that temperature and CO2 concentrations follow each other quite closely.
Recently, another European team finished an eight year project in Antarctica. The results are pretty much what you would expect.
Carbon dioxide levels are at their highest in 650,000 years.
Here is the story.
Carbon dioxide levels highest in 650,000 years
Nov. 25 ,2005
With the first in-depth analysis of the air bubbles trapped in the ice core of east Antarctica, scientists have discovered that today's atmospheric carbon dioxide levels are the highest in 650,000 years.
The analysis highlights the fact that today's rising atmospheric carbon dioxide concentration, at 380 parts per million by volume, is already 27 percent higher than its highest recorded level during the last 650,000 years, reported scientists in two papers in the Nov. 25 issue of the journal Science.
One study chronicles the stable relationship between climate and the carbon cycle during the Pleistocene (650,000 to 390,000 years ago). The second paper documents atmospheric methane and nitrous oxide levels over the same period.
Carbon dioxide and methane, known as greenhouse gases, are blamed for global warming. Scientists believe that humans have been accelerating the global warming trend by emitting more greenhouse gas through industrialization.
The ice core from Antarctica, containing hundreds of thousands of years-worth of atmospheric air samples within tiny bubbles trapped in the ice, adds to this argument by extending Earth's greenhouse gas record by 210,000 years.
The new records should help scientists better understand climate change and the nature of the current warm period on Earth, and may also aid researchers in reducing uncertainty in predictions of future climate change, said the researchers.
The greenhouse gas record also provides indirect evidence for abrupt climate change in the past, the researchers found. This suggests that abrupt climatic events on time scales relevant to societies may be common features of the last climatic cycles.
"We have added another piece of information showing that the timescales on which humans have changed the composition of the atmosphere are extremely short compared to the natural time cycles of the climate system," Thomas Stocker, senior author for both studies, said in a statement.
And here is the same story as reported from Australia.
Planet's gas levels highest on record
The Sydney Morning Herald
By Deborah Smith Science Editor
November 26, 2005
A STUDY of air bubbles trapped in a 3.2-kilometre long ice core from Antarctica, the oldest ever drilled, shows that greenhouse gases in the atmosphere today are at their highest levels in 650,000 years.
Carbon dioxide concentrations are 27 per cent higher than any of the past peaks evident in the frozen record of climate change, which spans six ice ages and six warmer interglacial periods, European researchers found.
In a separate study, US researchers have also found that sea levels are rising twice as fast today as they were 150 years ago.
These new pieces of evidence on the impact of human activity on climate come in the lead-up to a conference on how to combat global warming that opens in Montreal on Monday.
It took European scientists in Antarctica more than eight years to drill the 10-centimetre wide cylinder of ice, working in temperatures below minus 40 degrees. They chose a remote site called Dome Concordia, 1000 kilometres from the nearest base, where the low rate of snowfall had allowed an ancient section of ice to accumulate.
Carbon dioxide levels are now 380 parts per million, compared with previous peaks of below about 300 parts per million.
The ice core study, published in yesterday's issue of Science, confirmed that temperatures have been closely tied to greenhouse gas levels throughout this period in a way that climate modellers had predicted.
The US team, led by Kenneth Miller of Rutgers University, drilled 500-metre-deep cores of sediment along the local coast to determine where the shoreline had been in the past 100 million years. Its results were also published in Science.
The Americans found that sea levels had risen steadily by about 1 millimetre a year from 5000 years ago to 200 years ago. Sea level measurements since 1850, on the other hand, showed a rise of 2 millimetres a year, Professor Miller said. "Now, with solid historical data, we know it is definitely a recent phenomenon."
"It's a remarkable achievement," Dr Etheridge said. "To understand the future we need to understand the past."
Finally, here is another story on the sea rise in The Independent.
Perhaps you saw these stories in the American Media.
When I googled it,
I still didn't.
* Oz note, I did see the story on CBS and Yahoo this afternoon.
What it is About
Earthfamilyalpha Content II