UN Secretary-General Antonio Guterres has warned of a "dangerous disconnect" between what scientists and citizens are demanding to curb climate change - and what governments are actually doing about it.

Mr Guterres said global greenhouse gas emissions need to drop by 45% this decade but are currently forecast to increase by 14%.

"We are witnessing a historic and dangerous disconnect: science and citizens are demanding ambitious and transformative climate action," he said at a climate conference in Austria.

"Meanwhile many governments are dragging their feet. This inaction has grave consequences."

Mr Guterres said Russia's war in Ukraine risked worsening the crisis because major economies were "doubling down on fossil fuels" that are to blame for much of the emissions stoking global warming.

"New funding for fossil fuel exploration and production infrastructure is delusional," he said in a video message to the Austrian World Summit, initiated by former California governor Arnold Schwarzenegger. "It will only further feed the scourge of war, pollution and climate catastrophe."

Mr Guterres urged countries to instead end all coal use by 2040, with rich nations doing so by 2030, and focus on replacing fossil fuels with renewable sources of energy, such as solar and wind power.

"Renewables are the peace plan of the 21st century," he said.

Schwarzenegger, who has long campaigned against environmental pollution, said the war in Ukraine is another reason to stop using fossil fuels.

He cited research showing that Europe paid Russia tens of billions of dollars for energy imports in the first two months of the year.

"No matter how you look at it, we have blood on our hands because we are financing the war," said Schwarzenegger.

"We must do whatever it takes to eliminate our addiction to fossil fuels. We must be part of the solution, not part of the problem. Failure is no option here."