Humans must reduce net greenhouse gases emissions to zero “well before 2040” in order to ensure global warming does not go above 1.5 degrees Celsius by the end of the century, scientists have warned after carrying out a study using a sophisticated new computer model.
The analysis suggests that efforts to prevent temperatures rising to potentially dangerous levels may have to rely heavily on “negative emissions” technology that is still in its infancy.
Commenting on the study, Professor Richard Betts, head of climate impacts at the UK’s Met Office Hadley Centre, said the “important” research spelled out the “enormous challenge” ahead.
The new study, described in a paper in the journal Nature Communications, is one of the first to use the new FeliX computer model, which includes social and economic factors along with environmental ones.
One of the researchers, Dr Michael Obersteiner, of the International Institute for Applied Systems Analysis near Vienna, said: “The FeliX model … provides a unique systemic view of the whole carbon cycle, which is vital to our understanding of future climate change and energy.
“The study shows that the combined energy and land-use system should deliver zero net anthropogenic emissions well before 2040 in order to assure the attainability of a 1.5C target by 2100.”
This does not necessarily mean that humans would have to stop burning fossil fuels in little over 20 years, as the researchers included natural carbon sinks – such as forests – and the use of carbon-capture technology in their calculations.