Representatives from around the world are meeting in Bonn this week at the UN’s annual climate change conference. The main agenda is to flesh out the 2015 Paris Accord.

Which makes the Global Carbon Project’s report—released on Monday—saying that global greenhouse gas emissions are set to hit a record high in 2017, after staying flat for three years, all the more awkward.

Unsurprisingly, there appears to be a link to China, which has the world’s highest emissions. The coal-intensive northern China economy had—according to experts, dubious provincial data notwithstanding—seen a slump in the years when global emissions were flat. Now, the slump has eased as commodity prices have risen—and so have emissions.

China aims to have 42% renewables in the mix by 2030. But that would mean tens of billions of dollars worth of stranded coal assets, to the displeasure of the powerful coal lobby. This internal rebalancing will affect global climate change efforts substantially—as the rise in emissions this year shows.