The Greens want to double Perth's tree canopy by 2040 and have every resident living within five minutes of a green corridor.

The party wants the State Government to contribute $7.6 million for the plan, as well as $29 million in Commonwealth funds for its wider Green Cities policy.

WA senator Scott Ludlam said it was estimated Perth had lost 75 per cent of its original bushland and 80 per cent of wetlands.

He said green spaces acted as lungs for cities and helped to mitigate the impact of climate change.

Senator Ludlam said temperatures in some Perth suburbs could vary by as much as 6 degrees Celsius compared to others, depending on their canopy cover.

"Green suburbs such as Subiaco and Wembley Downs were found to be 4-6 degrees cooler than treeless suburbs such as Piara Waters, Clarkson and Butler on any given day," he said.

Senator Ludlam said the plan would need state, local and federal governments to work together, alongside neighbourhood groups and individuals.

He said heatwaves killed more Australians than other natural disasters and heat-related deaths were expected to double in Perth by 2050.

"If we all pitch in, we can get the urban canopy up to 40 per cent, that's the difference between life and death," Senator Ludlam said.

Indigenous cultural knowledge sought

As part of the strategy, the Greens also hope to establish an Aboriginal stewardship committee.

Senator Ludlam said the voices of traditional owners would show how to improve the city.

"We know that the plan won't work unless it captures the cultural knowledge of Aboriginals that have cultivated the land over tens of thousands of years," he said.

"They've taught us modern practices of suburban sprawl have had a devastating impact not only on biodiversity, but also Aboriginal culture."

Noongar elder Dr Noel Nannup, who provided advice on the plan, said it had positives for both for the city of Perth and Aboriginal people.

"The city can be a lonely place for some people," Dr Nannup said.

"If it's all car and cement it becomes an even more cold, hard and unforgiving place... I thought there's got to be a way to make it better," he said.

Dr Nannup said the plan was "streets ahead" of anything offered by the major parties, and the Greens understood Aboriginal people were not anti-development.