Global land surface temperatures might rise by an average of almost eight degrees Celsius by 2100, if significant efforts are not made to counteract climate change, according to a study published Wednesday by the University of Edinburgh.
Under a business-as-usual scenario, which assumes that there will be no significant change in people's attitudes and priorities, Earth's surface temperature is forecast to rise by 7.9 degrees Celsius over the land and by 3.6 degrees Celsius over the oceans by 2100, compared with 1750, the study warns.
In that case, it will breach the United Nations' safe limit of two degrees Celsius, beyond which the United Nations says dangerous climate change can be expected.
To carry out the study, researchers at the University of Edinburgh, first created a simple algorithm to determine the key factors shaping climate change and then estimated their likely impact on the world's land and ocean temperatures. Their work was based on historical temperatures and emissions data.
The method is more direct and straightforward than that used by the Intergovernmental Panel on Climate Change (IPCC), which uses sophisticated, but more opaque, computer models, according to the study.
Global temperature rise has slowed in the last decade, leading some to question climate predictions of substantial 21st Century warming, but a formal test shows that the recent slowdown is part of the normal behavior of the climate system, according to the study.
"Estimates vary over the impacts of climate change, but what is now clear is that society needs to take firm, speedy action to minimize climate damage," said Roy Thompson, a Professor at the University of Edinburgh.
The study has been published in the journal Earth and Environmental Transactions of the Royal Society of Edinburgh.