An Australian environmental consultant says the world needs to embrace nuclear power if it's serious about battling climate change.

Ben Heard, a former anti-nuclear advocate, says after extensively researching climate change mitigation he believes nuclear power is needed to decarbonise the planet.

Mr Heard says there's been major advances in renewable energy developments, but there's yet to be a genuine breakthrough to make it usable and economical on a large scale.

And he says the global demand for energy is sky-rocketing as populations increase and countries become more urbanised.

"I thought we were talking about urgent decarbonisation as this climate change is reaching a bit of a desperate point," Mr Heard said.

"We shouldn't be waiting around for breakthroughs, we need to get on with what we've got.

"That doesn't exclude wind, solar, wave, geothermal.

"But it has to include nuclear or we're not serious."