A novel research has predicted the rise of global temperatures this century by more than 7 degree Celsius, which could put the lives of many billions of people in jeopardy.
According to a report in the Telegraph, the study, carried out in unprecedented detail, projected that without "rapid and massive action", temperatures worldwide will increase by as much as 7.4 degrees C by 2100, from levels seen in 2000.
Previous estimates have concluded that the likely increase this century would probably be 2.4C (4.3F).
However, the new study by scientists at the prestigious Massachusetts Institute of Technology (MIT) included projected economic growth in developing countries and new information on the affect increased carbon emissions will have on biological processes, such as the capacity of the ocean to absorb greenhouse gases.
The results are based on 400 trials of the new system, each time using slightly different variations in data at the start to try and iron out errors.
Study co-author Ronald Prinn, Professor of Atmospheric Chemistry and director of MIT's Centre for Global Climate Change, said all the results resulted in an increase in temperatures.
The projections average out at a likely Earth temperature increase of 5.2 C this century, and conclude there is a 90 per cent chance the temperature change will be between 3.5 C and 7.4 C.
"Overall, they stacked up so they caused more projected global warming. There is significantly more risk than we previously expected," said Prinn.
"This increases the urgency for significant policy action. There is no way the world can and should take these risks," he added.
According to Friends of the Earth climate campaigner Tom Picken, if the new research by MIT is accurate, the results for the planet would be catastrophic.
He called for the world to try and reduce the chance of such an increase in temperatures by committing to reduce carbon emissions at the UN Climate Change Conference in Copenhagen at the end of this year.
"The consequences of such changes would be off the known scale. They are unthinkable," he said.
"A 7.4 C rise would mean severe ecosystem collapse worldwide, with total economic collapse in many parts of the world," he added.
"The planet would face resource wars between people, and you can safely say many, many hundred of millions of people would die," he further added.