Growing CO2 could cause 6 metre rise in sea level

A file picture of a Greenpeace message about reducing the CO2 emission level on Le Meridien Hotel, New Delhi.

Photo: AP

If the world fails to get the growing carbon emission under control, sea levels could rise by up to six metres, said a new study.

According to the study by the British Antarctic Survey (BAS), temperatures in the Antarctica were increased by six degrees Celsius during the past periods when the volume of high carbon dioxide (CO2) was high in the atmosphere.This could cause a sea level rise of up six metres, threatening coastal cities like London, New York and San Francisco, it said.Louise Sime, who led the BAS study, looked at ice cores to see how temperatures changed during periods of high carbon dioxide.

During the last period of high CO2, 125,000 years ago, she found temperatures were up to 6 degrees Celsius higher than present day levels.Such a hike in temperature could lead to a rise in sea levels of between 4 to 6 metres over hundreds of years as the ice sheets melt, The Telegraph reported.“We didn’t expect to see such warm temperatures, and we don’t yet know in detail what caused them. But they indicate that Antarctica’s climate may have undergone rapid shifts during past periods of high CO2.”

Dr Sime said the study suggests that current high levels of CO2 could also cause a rise in temperature. She said further research could predict the affect on sea level rise.“If we can pin down how much warmer temperatures were in Antarctica and Greenland at this time, then we can test predictions of how melting of the large ice sheets may contribute to sea level rise.”

It is the latest research to warn of the consequences of increased greenhouse gases on the Earth’s climate, The Telegraph Reported.All the recent studies are adding pressure on world leader to agree in international deal on climate change at a UN summit in Copenhagen this December.

A recent study appeared in Nature Geoscience found that carbon dioxide levels rose by almost a third in the last seven years. It warned that if the world continues to pump out pollution at such a rate it will cause temperatures to rise by six degrees Celsius, causing massive droughts, extinction of species and sea level rise.

Another study added to the urgency by claiming that the oceans are losing their ability to absorb CO2. Samar Khatiwala of Columbia University, found that the proportion of fossil fuel emissions absorbed by the oceans since 2000 may have decline by as much as 10 per cent.

“What our ocean study and other recent land studies suggest is that we cannot count on these sinks operating in the future as they have in the past, and keep on subsidising our ever-growing appetite for fossil fuels,” he said.But, Dr Wolfgang Knorr, of Bristol University, who has been studying the same subject said there is not yet enough evidence to prove that the Earth is losing its ability to absorb CO2.

Climate biggest issue in US's ties with India, China: Obama

President Barack Obama warned time is running out to fight global warming but said the US was determined to act and that climate was the biggest issue in its ties with countries like India and China often blamed for the stalled talks. Addressing a gathering of 100 world leaders at the UN climate change summit, Obama also pressed rapidly growing developing nations to "do their part as well", a veiled reference to emerging economies like India and China. He said no country alone can meet the challenges on climate change.

Obama however offered no new proposals that could serve as a catalyst to push the stalled talks on a UN climate pact. "We have put climate at the top of our diplomatic agenda when it comes to our relationships with countries as varied as China and Brazil, India and Mexico from the corner of Africa to the corner of Europe," he said.

His comments came shortly after the UN secretary general Ban Ki-moon said talks were moving too slowly and admonished the countries ahead of the Copenhagen summit of 190 countries in December aimed at sealing a deal to slow climate change. "Failure to reach broad agreement in Copenhagen would be morally inexcusable, economically short-sighted and politically unwise," Ban said.

Continuing, Obama said, "We understand the gravity of the climate threat. We are determined to act and we will meet our responsibility to future generations." He also warned there would be tough talking ahead of the Copenhagen climate change conference. "There should be no illusions that the hardest part of our journey is in front of us."

"But those rapidly growing developing nations that will produce nearly all the growth in global carbon emissions in the decades ahead must do their part as well," Obama said.