A new research of climate conducted on the Northern Hemisphere has revealed that temperature there has been warmer from past decade as compared to any time in the last 1,300 years. Some evidence has further pointed out that the comparison may go back till 1,700 years as well.

Through a Penn State news release, the team led by Michael Mann, associate professor of meteorology and geosciences and director of Penn State's Earth System Science Centre informed the present data has been gathered with the help of more sophisticated and advanced methods as compared to previous attempts.

Mann reported, “We looked at a much expanded database and our methods are more sophisticated than those used previously.”

The study was published in the Proceedings of the National Academy of Sciences. The researchers had written in the study, “Conclusions are less definitive for the Southern Hemisphere and globe, which we attribute to larger uncertainties arising from the sparser available proxy data in the Southern Hemisphere.”

Following the Industrial revolution, during the nineties a controversial hockey stick graph was obtained which displayed temperatures largely unchanged along the shaft of the stick, then a sharp increase - the top of the stick. The present findings have led to its comparison with the controversial graph of the nineties. Many people told this hockey stick graph to be inaccurate, as it was the first ever indication towards global warming and raised a huge debate over it.

Talking about the kind of methods used by the team to collect the data, Mann informed, “We used two different methods that are quite complementary in the assumptions they make about data, so that provides a test of the sensitivity of data to the methods used. We also made use of a far wider network of proxy data than previously available. Ten years ago, the availability of data became quite sparse by the time you got back to 1,000 AD, and what we had then was weighted towards tree-ring data; but now you can go back 1,300 years without using tree-ring data at all and still get a verifiable conclusion.”

According to the climate experts, the global temperature is rising and will continue to do so. The co-director of the Climate Change Research Centre at the University of NSW and climate scientist Andy Pitman said that the present findings “deeply reinforce the incontrovertible conclusion that we are warming rapidly outside natural variability.”

The research was supported by the National Science Foundation, U.S. Department of Energy and the National Oceanic and Atmospheric Administration