The lack of trees in around two-thirds of Australian suburbs is intensifying extreme heat effects, which could make these cities almost unliveable in the coming years according to new report.

The new RMIT and Greener Spaces Better Places Where Will All the Trees Be? report aims to understand to what extent urban density, population growth, rainfall and other factors influence local council efforts to increase their urban green space.

It found that in the last seven years alone the number of trees in 69 per cent of suburbs had dramatically dropped, and as a result, the report stated temperatures can be as much as 10C hotter.

More importantly, 71 of the 131 urban local government areas have a challenge factor rating of “high” or “very high” when it comes to taking action to reverse this trend.

According to lead author and associate professor Joe Hurley from RMIT’s Centre for Urban Research, because city greenery helped reduce the urban heat island effect, “it should be managed as critical infrastructure alongside communications, transport, water and energy.

“But all too often trees are traded away for other demands like urban development,” he continued.

The report found that Cairns was the top performer in this space with 83 per cent green cover, although the report does acknowledge that it has large tracts of rainforest within its borders. Victoria’s Yarra Ranges, Sydney’s Hornsby and Sutherland shires, and Tasmania’s Kingsborough Council round up the leaders.

On the other end, the report identified Melbourne as most at risk, with the southwest city of Wyndham having the lowest levels of greenery at just 5.4 per cent, and joined by other Melbourne local government jurisdictions Melton, Maribyrnong, Hobsons Bay and Hume.

South Australia’s Port Adelaide Enfield also joined them at the bottom of the list, while for Sydney, the municipalities found to be most at risk include Bayside, Botany Bay, Cumberland, Camden and Fairfield.

In terms of overall growth, Launceston and the Sunshine Coast have been the biggest movers, having seen almost 10 per cent of greenery growth in the last four years, while the Northern Territory’s Palmerston, Sydney’s Ryde and Burwood and Perth’s Kalamunda saw the largest reductions.

Blacktown in Sydney, Perth’s Bayswater and Fremantle, Melbourne’s Brimbank Council and Ipswich in Brisbane have been placed in the “high risk” category when it came to losing more of its greenery.

Hurley said that although it’s encouraging to see the longer-term trends start to turn around now, more work needs to be done as the losses still haven’t been made up yet.