Experts at the UN's annual climate change conference in Katowice, Poland, have urged nations to adhere to the path of the Paris agreement, which sets a global target of keeping the average temperature rise no higher than 2°C above preindustrial levels.

"This year is likely to be one of the four hottest years on record," Patricia Espinosa, the UN's climate chief, said in a news release from the United Nations Framework Convention on Climate Change, which opened Sunday.

"Greenhouses gas concentrations in the atmosphere are at record levels and emissions continue to rise. Climate change impacts have never been worse," she said. "This reality is telling us that we need to do much more — COP24 needs to make that happen."

The 24th Conference of the Parties to UNFCCC, or COP24, is tasked with finalizing detailed implementation guidelines for the landmark Paris treaty signed in 2015.

The conference comes amid a slew of reports warning of increasing greenhouse gas concentrations and emissions and their threat to health and other serious impacts, including a report on the effects of global warming of 1.5°C above preindustrial levels by the Intergovernmental Panel on Climate Change.

Espinosa stressed that all of these findings confirm the need to maintain the strongest commitment to the Paris agreement's aims of limiting global warming to well below 2°C and pursuing efforts toward 1.5°C.

"All our focus should be on reaching this aim and on building up ambition toward it," she said, adding the increasing public awareness and demand for solutions because of the clear evidence that the climate is changing has given countries strong backing for rapid action.

Michal Kurtyka, the COP24 president, was quoted in the release as saying, "The 2015 Paris agreement entered into force faster than any other agreement of its kind. I now call on all countries to come together, to build upon this success and to make the agreement fully functional.

"We are ready to work with all nations to ensure that we leave Katowice with a full set of implementation guidelines and with the knowledge that we have served the world and its people," he added.

To map out the detailed implementation guidelines for the Paris agreement as scheduled should be the core task of COP24.

Adhering to the path of the agreement, the implementation guidelines should embody the principles of equity, common but differentiated responsibilities, respective capabilities and in the light of different national circumstances, according to China's Policy and Actions for Addressing Climate Change (2018), which was published late last month.

The document calls on parties to promote the implementation of pre-2020 promises and actions to lay a mutual-trust foundation for post-2020 implementation of the Paris agreement.

Developed countries should offer more detailed information on the delivery of $100 billion of support for developing countries every year before 2020 and meet the reasonable financial demand from developing countries over climate change issues, it added.

At the 2009 Copenhagen conference, COP15, developed countries pledged $30 billion to a so-called Fast Start fund from 2010 to 2012 and a scale-up of aid to $100 billion a year by 2020.