Riccardo Valentini, University of Tuscia (Italy) & University of East Anglia (UK)
Valentini discusses a paper in the journal Nature Climate Change that suggests it is increasingly unlikely that global warming will be kept below an increase of 2C (3.6F) above pre-industrial levels, a study suggests.
Data show that global CO2 emissions in 2012 hit 35.6bn tonnes, a 2.6% increase from 2011 and 58% above 1990 levels.
The researchers say that emissions are the largest contributor to future climate change and a strong indicator of potential future warming.