Global emissions of CO2 in 2017 are projected to rise for the first time in four years, dashing hopes that a peak might soon be reached, according to new research from UK-based Tyndall Centre for Climate Change Research.
The main cause of the expected growth has been greater use of coal in China as its economy expanded. The report points out that China’s growth in fossil emissions will rise 3.5%.
Researchers are uncertain if the rise in emissions is a one-off or the start of a new period of CO2 build-up.
Scientists say that a global peak in CO2 before 2020 is needed to limit dangerous global warming this century.
Elsewhere, the report also maintained that CO2 emissions are expected to decline by 0.4% in the US and 0.2% in the EU, smaller declines than during the previous decade.
Increases in coal use in China and the US are expected this year, reversing their decrease s since 2013.
The news comes as policymakers and delegates have been meeting at the UN Climate Change Conference (COP23) in Bonn, Germany, this week (6-17 November, 2017).
Lead researcher Prof Corinne Le Quéré, director of the Tyndall Centre for Climate Change Research at UEA, said: “Global CO2 emissions appear to be going up strongly once again after a three year stable period. This is very disappointing.
“With global CO2 emissions from human activities estimated at 41 billion tonnes for 2017, time is running out on our ability to keep warming well below 2°C let alone 1.5°C.
“This year we have seen how climate change can amplify the impacts of hurricanes with more intense rainfall, higher sea levels and warmer ocean conditions favouring more powerful storms. This is a window into the future. We need to reach a peak in global emissions in the next few years and drive emissions down rapidly afterwards to address climate change and limit its impacts.”
Glen Peters of the CICERO Center for International Climate Research in Oslo who led one of the studies said: “The return to growth in global emissions in 2017 is largely due to growth in Chinese emissions, projected to grow by 3.5% in 2017 after two years with declining emissions. The use of coal, the main fuel source in China, may rise by 3% due to stronger growth in industrial production and lower hydro-power generation due to less rainfall.
“The growth in 2017 emissions is unwelcome news, but it is too early to say whether it is a one-off event on a way to a global peak in emissions, or the start of a new period with upward pressure on global emissions growth.”
The team flags that persistent uncertainties exist in our ability to estimate recent changes in emissions, particularly when there are unexpected changes as in the last few years.
“Even though we may detect a change in emission trend early, it may take as much as ten years to confidently and independently verify a sustained change in emissions using measurements of atmospheric concentrations of carbon dioxide,” said Peters.
“Policy makers in Bonn are preparing for the Global Stocktake under the Paris Agreement, that will start in 2018 and occur every five years, and this puts immense pressure on the scientific community to develop methods and perform measurements that can truly verify changes in emissions within this five-yearly cycle,” said Le Quéré.