Planet running the worst fever in centuries

Article SMH 23 June 2006
By John Heilprin in Washington
June 23, 2006
 
 THE earth is the hottest it has been in at least four centuries and perhaps in thousands of years.

The US National Academy of Sciences reached that conclusion in a broad review of scientific work requested by the US Congress.

In a report released on Wednesday it found the "recent warmth is unprecedented for at least the last 400 years and potentially the last several millennia".

A panel of leading climate scientists said the earth is running a fever and that "human activities are responsible for much of the recent warming".

Their 155-page report said average global surface temperatures in the northern hemisphere rose about half a degree Celsius during the 20th century.

The report was requested in November by the chairman of the House of Representatives science committee, Sherwood Boehlert, a Republican, to address naysayers who question whether global warming is a major threat.

The Bush Administration also has maintained that the threat is not severe enough to warrant new pollution controls that the White House says would have cost 5 million Americans their jobs.

The climate scientists Michael Mann, Raymond Bradley and Malcolm Hughes had concluded the northern hemisphere was the warmest it has been in 2000 years.

The panel looked at how other scientists reconstructed the earth's temperatures going back thousands of years, before there was data from modern scientific instruments.

For all but the most recent 150 years, scientists from the academy relied on "proxy" evidence from tree rings, corals, glaciers and ice cores, cave deposits, ocean and lake sediments, boreholes and other sources. They also examined indirect records such as paintings of glaciers in the Alps.

Combining that information gave the panel "a high level of confidence that the last few decades of the 20th century were warmer than any comparable period in the last 400 years", the academy said.

Overall, the panel agreed that the warming in the past few decades of the 20th century was unprecedented over the past 1000 years, though relatively warm conditions persisted about AD1000, followed by a "Little Ice Age" from about 1500 to 1850.

Between AD1 and 1850, volcanic eruptions and solar fluctuations were the main causes of changes in greenhouse gas levels. But those temperature changes "were much less pronounced than the warming due to greenhouse gas" levels by pollution since the mid-19th century, it said.

The academy is a private organisation chartered by Congress to advise the government on science.

Ends 
 

Swim for climate change on Sunday

Friday, 9 June 2006  

DR MATTHEW Nott, along with Grant Prowse and Jessica Greenwood, will be swimming across Lake Jindabyne on Sunday to raise awareness of the problem of carbon dioxide emissions with its threat of climate change. 

They will start off from the Jindabyne foreshore and swim to East Jindabyne and back, some three to three and a half hours in the water. 

The water temperature will be eight degrees and that is a reminder to everyone that from the ocean to the highest peak in the world is a distance of eight kilomtres. 

That thickness of earth supports all life, said Dr Nott, and is being polluted by 7 billion tonnes of carbon through carbon dioxide emissions.Dr Nott and his fellow swimmers will be accompanied by kayakers from Tathra

 and a medical team on a boat.

ends.