Global mean temperature at the Earth's surface is set to reach one degree Celsius above pre-industrial levels this year, according to the latest data released Monday by Britain's Met Office.
Based on data from January to September, the HadCRUT dataset jointly run by the Met Office and the Climate Research Unit at the University of East Anglia shows 2015 global mean temperature at 1.02 degrees Celsius above pre-industrial levels.
"We've had similar natural events in the past, yet this is the first time we're set to reach the one degree Celsius marker and it's clear that it is human influence driving our modern climate into uncharted territory," said Stephen Belcher, Director of the Met Office Hadley Center.
Early indications suggest 2016 will be similarly warm and while it's more difficult to say exactly what will happen in the years immediately after that, it is expected that warming will continue in the longer term, according to the Met Office.
"This year marks an important first but that doesn't necessarily mean every year from now on will be a degree or more above pre-industrial levels, as natural variability will still play a role in determining the temperature in any given year," said Peter Stott, who leads the Climate Monitoring and Attribution team in the Met Office.
"As the world continues to warm in the coming decades, however, we will see more and more years passing the one degree marker - eventually it will become the norm," Stott added.
Limiting the rise in Earth's temperatures to below two degrees Celsius above pre-industrial levels is the core goal of the United Nations' upcoming climate summit in Paris.
Research suggests it is still possible to limit warming to two degrees Celsius above pre-industrial levels. However, the later that global CO2 emissions peak, the faster subsequent emissions cuts would need to be in order to keep global temperature rise below the limit, according to the Met Office.
