In a speech on renewable energy, António Guterres cited “clear market distortion” in favor of fossil fuels by President Trump and others but called the transition to cleaner energy economically inevitable.

The United Nations secretary general’s speech on Tuesday was billed as a rare, optimistic one on the future of climate change.

Look at the cold, hard economic data, António Guterres, the U.N. chief, said, and you will see that the world’s transition from polluting fossil fuels to cleaner renewable energy is “unstoppable.”

But then there was the matter of the world’s largest economy, the United States.

President Trump pulled the United States out of the main international agreement to limit climate change and has, with Congress, sought to cripple domestic wind and solar power industries, the growth of electric vehicles and climate science research.

The United States and those that follow its lead are “missing the greatest economic opportunity of the 21st century,” said