UNITED NATIONS — U.N. Secretary-General Antonio Guterres says the world has reached “a pivotal moment” in global warming and risks runaway climate change if leaders don’t act in the next two years.

He is telling world leaders at the U.N. General Assembly that they aren’t doing enough to combat what he calls “a direct existential threat” that is moving faster than people are working to combat it.

He notes that thick, permanent sea ice north of Greenland began to break up this year for the first time.

He’s calling for making sure the international Paris climate change agreement is implemented. U.S. President Donald Trump has announced he’s withdrawing his country from the pact.

Guterres is planning a climate summit next year.

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