Despite the call of Swedish activist Greta Thunberg towards a more ambitious climate action, presidents and prime ministers of the world’s largest emitting economies at the United Nations failed to commit to additional goals to further reduce their greenhouse emissions.

The Paris Agreement hopes to limit the temperature increase to 1.5ºC, which means most countries will have to achieve net-zero global emissions by 2050. That’s why UN chief Antonio Guterres had asked leaders to attend the climate summit with plans on how to meet that target.

A coalition of 77 smaller countries said they were committed to achieving net-zero emissions by 2050 and 70 countries expressed their intention to set a more ambitious climate plan next year, evidence of “a boost of momentum and ambition,” Guterres said in his closing remarks.

This showed signs of progress but wasn’t considered sufficient, as “most of the major economies fell woefully short” of enhancing their ambition, said Andrew Steer, president and CEO of the World Resources Institute. A stronger action will be needed to reach carbon neutrality.

The key question that remains is how countries will integrate climate action into their policies to reach carbon neutrality. Former French climate ambassador and CEO of the European Climate Foundation Laurence Tubiana said the path to net-zero emissions “is something we are just discovering.”

The United Kingdom and France, which have already legislated to become carbon neutral by 2050, have been warned by their climate advisors that without new and robust carbon-cutting measures, they won’t be on track to meet the 2050 goal. UK prime minister Boris Johnson said they will look to be more ambitious.

China, the world’s largest emitting country, failed to give a significant announcement. Wang Yi, a special representative of Xi, said China would meet its Paris pledge but made no suggestion of when and how Beijing would hike its climate plan and peak its emissions.

Meanwhile, European Union Council president Donald Tusk said it was only a matter of time for the bloc to adopt net zero emissions by 2050 as its target – but gave few details of how the world’s largest economic bloc was going to transfer away from fossil fuels.

The next step towards climate action will be the UN’s Conference of Parties (COP) in Santiago de Chile in December. Nevertheless, time is running out. Global emissions continue to rise year-on-year – increasing the gap between the 1.5°C goal and current pathways to get there and closing the door to incremental emission reductions.