BANGKOK — The spike in global temperatures is bigger than any seen in the past 11,300 years, scientists said in research published yesterday. Temperatures have not risen as fast as they are now in the 11,300 years that the US researchers studied and climate models showed that by the end of this century, temperatures would be warmer than any time since the last ice age, they said in the journal Science.
Based on fossil samples and other data collected from 73 sites around the world, scientists have been able to reconstruct the history of the planet's temperature from the end of the last Ice Age around 11,000 years ago to the present. They have determined that the past 10 years have been hotter than 80 per cent of the last 11,300 years. But virtually all the climate models evaluated by the Intergovernmental Panel on Climate Change predict that the Earth's atmosphere will be hotter in the coming decades than at any time since the end of the Ice Age, no matter what greenhouse gas emission scenario is used, the study found.
"We already knew that on a global scale, Earth is warmer today than it was over much of the past 2,000 years," said Shaun Marcott, the lead author of the study, which was published in Science. "Now we know that it is warmer than most of the past 11,300 years. This is of particular interest because the Holocene spans the entire period of human civilisation," said Marcott, who is a post-graduate researcher at Oregon State University.
The data show that temperatures cooled by 0.8 degrees Celsius over the past 5,000 years, but have been rising again in the past 100 years, particularly in the northern hemisphere where land masses and population centres are larger. The climate models project that average global temperatures will rise by 1.1 to 6.3 degrees Celsius by the end of the century, depending on the level of CO2 emissions resulting from human activities, the researchers found. "What is most troubling is that this warming will be significantly greater than at any time during the past 11,300 years," said Peter Clark, a paleoclimatologist at Oregon State. — DPA/Reuters
