Leaders of the world’s 20 biggest economies have agreed to tackle “the critical and urgent threat of climate change” but angered activists by offering few concrete commitments to limit global warming.

Wrapping up a summit in Rome, the leaders of the G20 pledged on Sunday to stop funding coal-fired power plants in poor countries, but set no timetable for phasing it out at home.

They agreed to cap the global rise in temperature to 1.5C (2.7F) above the pre-industrial average but made only a vague commitment to seek carbon neutrality “by or around mid-century”.

This was the result of days of tough negotiation among diplomats, and it leaves huge work to be done at the broader United Nations COP26 climate summit in Scotland, which starts this week.

While Italian Prime Minister Mario Draghi and French President Emmanuel Macron described the G20 as a success, the outcome disappointed the chief of the UN as well as the leader of the United Kingdom.

Draghi said the declaration went further on climate than any G20 statement before it. He noted that it referred to limiting global warming at the 1.5C threshold that scientists say is vital to avoid disaster.

“We changed the goalposts,” Draghi told reporters.

‘Hopes unfulfilled’But UK Prime Minister Boris Johnson called the G-20’s commitments mere “drops in a rapidly warming ocean”, while UN Secretary-General Antonio Guterres agreed the outcome was not enough.

“While I welcome the #G20′s recommitment to global solutions, I leave Rome with my hopes unfulfilled – but at least they are not buried,” Guterres tweeted. “Onwards to #COP26 in Glasgow.”

The G20, which includes Brazil, China, India, Germany and the United States, represent more than three-quarters of the world’s greenhouse gas emissions, and the UK had hoped for a “G20 bounce” going into the Glasgow COP26 meeting. Environmentalists and scientists have described the UN conference as the world’s “last best hope” for nailing down commitments to limit the global rise in temperature to 1.5C above the pre-industrial average.

That threshold is what UN experts say must be met to avoid a dramatic acceleration of extreme climate events like droughts, storms and floods, and to reach it, they recommend net-zero emissions should be achieved by 2050.

The stakes are enormous – among them the very survival of low-lying countries, the effect on economic livelihoods the world over and the stability of the global financial system.

The UK pushed hard for a commitment to achieve net-zero emissions, but in the end, the G20 leaders arrived at a compromise to achieve that goal “by or around mid-century,” not a set year.

The US and the European Union have already set 2050 as their deadline for reaching net-zero emissions, while China, Russia and Saudi Arabia are aiming for 2060. The leaders of those three countries did not come to Rome for the summit.

Russia, China ‘didn’t show up’Before leaving Rome, US President Joe Biden called it “disappointing’ that G20 members Russia and China’ basically didn’t show up” with commitments to address the scourge of climate change ahead of the UN climate conference.

Russian leader Vladimir Putin and Chinese President Xi Jinping are not expected to attend the conference in Glasgow, although they are sending senior officials to the international COP26 talks.

“The disappointment relates to the fact that Russia … and China basically didn’t show up in terms of any commitments to deal with climate change. And there’s a reason why people should be disappointed,” Biden said, adding: “I found it disappointing myself.”

Canadian Prime Minister Justin Trudeau also signalled he would have liked to see more ambition.

“There’s no question that Canada, along with a number of other countries, would have liked stronger language and stronger commitments on the fight against climate change than others,” he told reporters.

The UK pushed hard for a commitment to achieve net-zero emissions, but in the end, the G20 leaders arrived at a compromise to achieve that goal “by or around mid-century,” not a set year.

The US and the European Union have already set 2050 as their deadline for reaching net-zero emissions, while China, Russia and Saudi Arabia are aiming for 2060. The leaders of those three countries did not come to Rome for the summit.

Russia, China ‘didn’t show up’Before leaving Rome, US President Joe Biden called it “disappointing’ that G20 members Russia and China’ basically didn’t show up” with commitments to address the scourge of climate change ahead of the UN climate conference.

Russian leader Vladimir Putin and Chinese President Xi Jinping are not expected to attend the conference in Glasgow, although they are sending senior officials to the international COP26 talks.

“The disappointment relates to the fact that Russia … and China basically didn’t show up in terms of any commitments to deal with climate change. And there’s a reason why people should be disappointed,” Biden said, adding: “I found it disappointing myself.”

Canadian Prime Minister Justin Trudeau also signalled he would have liked to see more ambition.

“There’s no question that Canada, along with a number of other countries, would have liked stronger language and stronger commitments on the fight against climate change than others,” he told reporters.