Countries need to double the pace of measures to enhance energy efficiency if global climate targets are to be met, the International Energy Agency (IEA) said in a report Wednesday.

Record high energy costs last year helped to spur the take-up of measures such as replacing gas boilers with heat pumps and switching to LED lightbulbs, but the rate of progress in energy efficiency has since slowed, the IEA said.

This year’s U.N. climate talks begin on Thursday in the United Arab Emirates (UAE) and will be the first global assessment of progress since the landmark Paris Agreement in 2015. It aimed to limit global warming to well below 2 degrees Celsius (3.6 degrees Fahrenheit) while aiming for a cap of 1.5 degrees Celsius.

"The world’s climate ambitions hinge on our ability to make the global energy system much more efficient," IEA Executive Director Fatih Birol said.

"If governments want to keep the 1.5 degree Celsius goal within reach while supporting energy security, doubling energy efficiency progress this decade is critical," he said.

The IEA said investments have led to energy being used 1.3% more efficiently this year compared with last year but that the improvement rate had slowed from a 2% increase in 2022.

Energy efficiency needs to double from that level to 4% a year for climate targets to be met, the IEA said.

"The findings of this report are a stark warning to the leaders gathering shortly at the COP28 climate conference in Dubai that they all need to commit to stronger action on efficiency and to deliver on it."

The slower global rate of efficiency improvements masked some strong gains at the national level, IEA said.

After improving energy intensity by 8% in 2022, the European Union was set to post a 5% improvement this year, while the United States was on track for a 4% improvement.

The U.N. conference in UAE is expected to attract 70,000 participants from around 200 countries.