Global carbon dioxide emissions from fossil fuels are on track to increase by 2 percent in 2017, according to a new assessment from the Global Carbon Project. The projected rise, which follows three years of flat growth, signals that the world's emissions have not yet peaked, complicating efforts to meet the temperature targets of the Paris Agreement.
The findings were released as delegates gathered in Bonn, Germany, for the 23rd Conference of the Parties (COP23) to the United Nations Framework Convention on Climate Change. The data, published in the journals Nature Climate Change, Environmental Research Letters, and Earth System Science Data Discussions, indicate that total human-caused emissions will reach 41 billion metric tons in 2017.
Corinne Le Quéré, lead researcher and director of the Tyndall Centre for Climate Change Research at the University of East Anglia, expressed disappointment at the results. “Time is running out on our ability to keep warming well below 2°C, let alone 1.5°C,” she said in a statement accompanying the report.
The projected rise is driven largely by increased coal consumption, which reversed a recent declining trend. The report attributes part of the increase to economic growth, noting that U.S. GDP expanded by about 2.2 percent in 2017.
U.S. Emissions Decline Slows
In the United States, emissions are expected to fall by 0.4 percent in 2017, a much smaller decline than the 1.2 percent annual average over the past decade. The slowdown reflects a mix of factors, including a rebound in coal use. Despite the federal government's decision to withdraw from the Paris Agreement, many states, cities, and corporations have pledged to continue climate action.
Rob Jackson, chair of the Global Carbon Project and a professor at Stanford University, said the results are discouraging but not cause for despair. “In the U.S., cities, states, and companies have seized leadership on energy efficiency and low-carbon renewables that the federal government has abdicated,” he said.
The report's country-level breakdown provides a tool for policymakers at COP23 to target their efforts. While the U.S. and some European nations have seen emissions decline, other major economies, particularly in Asia, are still increasing their fossil fuel use.
The three-year plateau in emissions had led some experts to speculate that the world might be approaching a peak. The new data, however, suggest that the plateau was a temporary pause rather than a turning point. Le Quéré noted that the window for limiting warming to well below 2°C is closing, and the current trajectory is not consistent with that goal.
The report's release at the start of COP23 adds urgency to the negotiations. Delegates are tasked with developing rules for implementing the Paris Agreement, and the new emissions data underscore the gap between current pledges and the reductions needed to meet the temperature targets.
While the global trend is upward, the report also highlights regional differences. The U.S. decline, though modest, is still a decline, and the country's subnational actors are pushing for more aggressive action. Whether these efforts can offset federal inaction remains to be seen.
For now, the message from scientists is clear: the world is moving in the wrong direction, and the pace of change must accelerate. The report serves as a reminder that the commitments made under the Paris Agreement are not yet sufficient to avoid the worst impacts of climate change.