Policymakers at this week's international climate negotiations in Germany meet amid sobering news that gives their work new urgency. After three years of flat growth, global fossil fuel emissions are rising again, according to a series of reports from the Global Carbon Project, a group chaired by Stanford University scientist Rob Jackson.
"This year's result is discouraging, but I remain hopeful," said Jackson, the Michelle and Kevin Douglas Provostial Professor in Stanford's School of Earth, Energy & Environmental Sciences. "In the US, cities, states and companies have seized leadership on energy efficiency and low-carbon renewables that the federal government has abdicated."
The Global Carbon Project's report appears in the 13 Novenber Environmental Research Letters with detailed data published simultaneously in an Earth System Science Data Discussions paper led by Corinne Le Quéré of the University of East Anglia, who is also part of the Global Carbon Project.
Together, they forecast that global fossil fuel emissions will reach a record 37 billion tons of carbon dioxide in 2017, with total emissions reaching a record 41 billion tons, including deforestation. Atmospheric carbon dioxide concentration reached 403 parts per million in 2016, and is expected to increase by 2.5 parts per million in 2017.
Leading that increase is China, where emissions are projected to grow by approximately 3.5 per cent in 2017. Coal use there is up an estimated 3 per cent, oil use is up 5 per cent and natural gas use is up nearly 12 per cent.
"The green economy is booming in China and elsewhere, but growing energy demands are also being met with new oil, coal and natural gas infrastructure," Jackson said.
Jackson led a second study for the Global Carbon Project on carbon dioxide removal from the atmosphere, also in the 13 November Environmental Research Letters, and co-authored a related commentary in Nature Climate Change on tracking emissions to the Paris agreement.
Carbon dioxide concentrations in the atmosphere have increased from approximately 277 parts per million at the dawn of the Industrial Era to 403 parts per million as of 2016. Deforestation and land-use change drove those increases until about 1920, when fossil fuel use became the dominant source of carbon emissions. In the past decade, fossil fuels and industry have accounted for 88 percent of total carbon emissions.
The years between 2014 and 2016 stand out because emissions barely budged despite a growth in global gross domestic product. This was the first time that global emissions were decoupled from economic output - a development driven by reduced coal use in the United States and China, as well as energy efficiency improvements and growth in renewable energy around the world.
Carbon dioxide emissions have decreased despite growing economic activity in 22 countries representing 20 per cent of global emissions. Among them, the United States is expected to see a 0.4 per cent decline in emissions this year, and the European Union 0.2 per cent.
Still, overall global carbon emissions are unlikely to decrease in 2018, according the researchers.
Although India's emissions are projected to grow by just 2 per cent this year - a dramatic shift from over 8 per cent per year during the last decade - they could easily bump up rapidly if that country's economy recovers from a recent downturn. Elsewhere, World Bank forecasts for growth in global GDP could have similar effects on emissions.
Growth in renewables and improved energy efficiency still provide reasons to be optimistic, according to Jackson.
Countries installed a record amount of renewable generating capacity in 2016, and 2017 should see another record set.
"Prices for wind and solar power are plummeting, and batteries and storage are helping to balance supply and demand for electricity," says Jackson. "The world's energy future is changing before our eyes."
Jackson is also a senior fellow at the Stanford Woods Institute for the Environment and the Precourt Institute for Energy.
The Global Carbon Project, part of the International Council for Science and Future Earth, addresses climate change by providing regular analyses of the global carbon cycle.
(Also see: 15,000 scientists in 184 countries warn about negative global environmental trends)