But the rate of climate change is rapidly outstripping mankind's response. With just one Celsius of warming so far, Earth is blighted by raging wildfires, extreme drought and mega-storms made worse by rising sea-levels.
"Even as we witness devastating climate impacts causing havoc across the world, we are still not doing enough, nor moving fast enough, to prevent irreversible and catastrophic climate disruption," Guterres said.
Some of the nations most at risk from climate change will have the chance Monday to plead the case for immediate action. Frank Bainimarama, prime minister of Fiji and president of last year's COP climate talks, said nations must act now to stave off disaster.