UN Secretary-General Antonio Guterres on Saturday called for a worldwide "state of climate emergency" to tackle global warming.

Five years after the Paris Agreement on climate change, the world is still not going in the right direction, he told the Climate Ambition Summit co-convened by the United Nations and the governments of Britain and France.

The Paris Agreement promised to limit temperature rise to as close to 1.5 degrees Celsius as possible. But the commitments made in Paris were far from enough to get there. And even those commitments are not being met, he noted.

"Carbon dioxide levels are at record highs. Today, we are 1.2 degrees hotter than before the industrial revolution. If we don't change course, we may be headed for a catastrophic temperature rise of more than 3 degrees this century. Can anybody still deny that we are facing a dramatic emergency?" he asked.

"That is why today I call on all leaders worldwide to declare a state of climate emergency in their countries until carbon neutrality is reached."

Some 38 countries have already done so, recognizing the urgency and the stakes. All other countries should follow, said Guterres.