STORY: “The climate time bomb is ticking…”

UN Secretary General Antonio Guterres says there's little time to lose in tackling climate change.

And rich countries need to slash emissions sooner.

His latest call came in a recorded address after a new assessment from scientists.

“Humanity is on thin ice, and that ice is melting fast. As today’s report of the Intergovernmental Panel on Climate Change (IPCC) details, humans are responsible for virtually all global heating over the last 200 years."

Guterres said the panel’s latest synthesis report should be seen as a survival guide for humanity.

He urged developed countries to commit to reaching net zero emissions by the earlier date of around 2040.

According to the IPCC, emissions must be halved by the mid-2030s if the world is to have any chance of limiting temperature rise to 1.5 degrees Celsius above pre-industrial levels.

That’s a key target in the 2015 Paris accord.

But average temperatures have already spiked more than a degree, fueling more extreme weather events worldwide.

Current estimates say the planet could warm more than 3 degrees by the end of the century.

And just meeting existing pledges may not cut it.

Here's the panel's chair, Hoesung Lee:

“We are walking when we should be sprinting.”

Nations are expected to update climate pledges by 2025 – this latest assessment will serve as a guide.

If there's any chance of making the necessary emissions cuts, the panel says, the world needs to transform agriculture and eating habits and speed up the transition to green energy.

The warning comes while it estimates nearly half the planet's population is already vulnerable to climate impacts.