The global temperature rising more than 1.5 degrees Celsius in the next two decades is scarier than a nuclear war, said President Joe Biden on Sunday in Vietnam.

"The only existential threat humanity faces even more frightening than a nuclear war is global warming going above 1.5 degrees in the next 20 — 10 years," on Sunday.

"That'd be real trouble. There's no way back from that," Biden said, .

"And so, there's a lot we can do in the meantime."

Biden's trip to Vietnam came . In his comments, he noted the increasing global focus on climate change.

"Many of you who are foreign policy experts have been engaged for a long time. Did you ever think you'd be sitting at a G20 conference where everyone was preoccupied with the notion of global warming?" Biden said. "Not a joke. Did you ever think that?"

It has been a brutal summer.

On Wednesday, the European Union's announced the .

"The dog days of summer are not just barking, they are biting. Our planet has just endured a season of simmering — the hottest summer on record. Climate breakdown has begun," the .

"Scientists have long warned what our fossil fuel addiction will unleash.  Our climate is imploding faster than we can cope with extreme weather events hitting every corner of the planet," Guterres said. "Surging temperatures demand a surge in action.  Leaders must turn up the heat now for climate solutions. We can still avoid the worst of climate chaos — and we don't have a moment to lose."

In his comments in Hanoi, Biden talked about the importance of wealthier nations supporting less wealthy nations to prepare for and adapt to the implications of climate change.

"If we have the economic capacity, we — those nations should be getting together and providing help for the nations that don't have the wherewithal to do it — the economic wherewithal and the infrastructure wherewithal," Biden said.

For example, "Angola has the capacity to generate megawatts of energy through solar energy. They don't have the economic means to do that. Isn't it in the interest of the whole world if they are, in fact, able to generate significant capacity" of energy from solar energy, and "to prevent carbon from being released in the air? I think that it is," Biden said.