UN climate chief Simon Stiell said the world "cannot afford to stumble" as climate experts gathered in the German city of Bonn on Monday for the UN's annual June climate meetings.
Opening the conference, Stiell said "climate action will need to move at a much, much faster pace" if the goal of limiting global warming to 1.5 degrees Celsius is to be achieved.
He added that the world is currently on course for 2.7 degrees of global heating, down from initial estimates of 5 degrees before international co-operation to tackle climate change began under the UN's leadership.
The meeting in Bonn is crucial to achieving further reductions in warming, Stiell said. "There's a long and steep road ahead," he added.
Stiell, from the Caribbean island nation of Grenada, leads the UN's Framework Convention on Climate Change (FWCC), headquartered in Bonn.
Almost 6,000 delegates are expected to attend the annual 10-day gathering in preparation for the 29th Conference of Parties (COP29) talks in Azerbaijan in November.
The main issue on the table at the negotiations is climate finance. Industrialized countries have promised to support poorer nations hit by the consequences of climate change with billions in aid.
The loss and damage fund - as the financing has come to be known - was first formally adopted at the 27th Conference of Parties (COP) meeting in Egypt in 2022, with the aim of raising $100 billion for poorer nations every year.
A backlash against climate policies and global economic struggles since the coronavirus pandemic have limited wealthier countries' willingness to find the requisite funds, however, with the target believed to have been missed in 2023.
Germanwatch climate expert David Ryfisch told dpa that the conference in Bonn will be crucial. "There is an urgent need to rebuild trust, because the fact that the annual 100 billion was only exceeded in 2022 has permanently damaged trust between industrialized and developing countries," he said.
Western countries are demanding that other wealthy nations, including the Gulf states, also contribute to climate payments. "The challenge is that we have a huge gap between what is needed and what is actually provided," said Ryfisch.
It is unlikely that concrete draft texts for the COP29 talks in Azerbaijan's capital Baku will be presented in Bonn. Nonetheless, the conference is likely to be "very intense," said Jan Kowalzig, a German climate expert at the aid organization Oxfam.
"In recent years, expert discussions have been held at a technical level, but this year there will be concrete negotiations," Kowalzig told dpa. "We're really getting down to business now so that there is a draft decision before Baku and this key issue can actually be decided in Baku," he added.
Kowalzig concluded: "This round here in Bonn is very, very important. We look forward to seeing how the negotiations go."
