Global carbon dioxide (CO2) emissions from fossil fuels are set to hit a record high in 2025, increasing 1.1 percent over 2024, according to a study highlighted Thursday at the 30th United Nations Climate Change Conference (COP30) in Brazil's Amazonian city of Belem.

The Global Carbon Budget 2025, produced by the international scientific consortium Global Carbon Project, estimates that fossil CO2 emissions will reach 38.1 billion tonnes this year, as growth in global energy demand continues to outpace the expansion of renewable energy.

The report warns that the goal of slowing global warming to 1.5 degrees Celsius is out of reach under current circumstances, and that natural carbon sinks, such as oceans and forests, are weakening due to climate change.

"With CO2 emissions still increasing, keeping global warming below 1.5 degrees Celsius is no longer plausible," said Professor Pierre Friedlingstein of the University of Exeter, who led the study.

"The remaining carbon budget for 1.5 degrees Celsius, 170 billion tonnes of carbon dioxide, will be gone before 2030 at the current emission rate. We estimate that climate change is now reducing the combined land and ocean sinks – a clear signal from Planet Earth that we need to dramatically reduce emissions," he explained.

While progress has been made, it is not enough, researchers said.

"Efforts to tackle climate change are visible, with 35 countries succeeding in reducing their emissions while growing their economies," said Corinne Le Quere, a professor from the University of East Anglia.

However, she cautioned, "progress is still much too fragile to translate into the sustained decreases in global emissions needed to tackle climate change. The emerging impact of climate change on carbon sinks is worrying and stresses further the need for urgent action."