The world’s rate of carbon emissions is rising again after staying steady for three years, according to a comprehensive study released today.
The Global Carbon Budget report, produced by a team of 77 scientists from 57 organisations around the world, brings together the most accurate information available each year about humanity’s carbon output.
Global emissions held steady at 36.2 gigatonnes of carbon dioxide per year from 2014 to 2016, but they are on track to hit a new record high of 36.8 gigatonnes in 2017.
The single biggest cause of the rise is an increase in emissions from China, already the world’s biggest emitter, which had fallen slightly in recent years. This was combined with lacklustre cuts in the US and EU. One bright spot was a large drop in the growth rate of India’s emissions (from 6% a year to 2%), though it is most likely temporary.
Flat emissions in recent years were particularly remarkable because they were accompanied by worldwide economic growth. Previous slowdowns in carbon output have only occurred as a result of major economic trouble, such as the collapse of the Soviet Union and the global financial crisis of 2007-2008.
The good news, according to environmental economist Frank Jotzo of the Australian National University, is that economic activity on average produces less carbon emissions than it used to.
“The world is still reducing its emissions intensity by about 1.5% a year,” he says, referring to the amount of CO2 emitted per dollar of GDP.
In an accompanying paper published in Environmental Research Letters, several of the report’s authors argue “negative emissions” technologies that actively remove carbon from the atmosphere will be necessary to keep global warming below 2 degrees over pre-industrial temperatures.
Pep Canadell, a geoscientist at Australia’s CSIRO and head of the Global Carbon Project that produces the carbon budget report each year, says that the findings are disappointing.
“We don’t need to make a big deal out of it,” he told a press briefing, “but it’s the opposite of what we would like to see happening.”