Tree change the key to tackle temperature rises

City of Stirling increases tree canopy coverage in a bid to combat climate change.


Jamie Smith

City of Stirling residents plant trees to increase local canopy coverage.

Global warming is quickly becoming a major issue in the world as the environment is plundered for resources, but Perth local governments are trying to make a change.

In the past month the world has watched as the planet’s biggest rainforest – the Amazon – burned at an unprecedented rate.

BBC News reported more than eighty thousand fires had broken out this year, most of them due to farmers clearing land to plant crops.

The Amazon is widely regarded as “the lungs of the world” as it is a massive carbon store, and provides a large quantity of the world’s oxygen.

It is also home to one of the largest ecosystems on Earth. What happens in the Amazon has a worldwide effect.

Jörg Imberger, an environmentalist and prominent water researcher from the University of Western Australia, said the situation in the Amazon was a “bloody disaster”.

“But who cares about it? Do you see any positive action out there? When that building went on fire in France, Notre Dame, they raised 80 billion dollars in ten days,” Prof. Imberger said.

“The Amazon burns down, people talk about it but they don’t do anything about it.”

Prof. Imberger said he believed “nobody [was] serious about […] global warming”.

However, in Perth at least one local government is being proactive and trying to reverse rising temperatures in its suburbs.

The City of Stirling implemented a new tree planting program after its Urban Forest Plan studies showed suburbs with minimal canopy cover could be up to six degrees Celsius hotter than those with shade.

Under the plan, the City of Stirling targeted an 18 per cent increase in canopy cover by 2040 and by using a wide variety of trees aims to restore cooler temperatures and promote a healthier ecosystem.

In 2009 the City committed to planting 1 million new trees and shrubs, and by 2018 it had planted more than 600,000 trees and shrubs.

However, in the past six years, the city lost 1.2 million square meters of canopy with two-thirds of the loss due to land being cleared for private development.

City of Stirling Mayor Mark Irwin said the council was only halfway into the program and tree planting events had been set up for volunteers to lend a helping hand.

“It is about recognising we’ve got a real issue with our tree canopy declining throughout the City of Stirling, so we put in place a strategy to ensure that we try to address that, but also compensate for the tree loss,” Mayor Irwin said.

The Council set up tree planting events where volunteers could lend a helping hand.

“We have got to increase our coverage by at least 50 percent to reach our target of 18 per cent,” he said.

“Currently, we have a tree canopy coverage of about 12 per cent so it is certainly lower than we would like it to be and there are areas in the city where it is incredibly low.”

He said the council was aware the target of 18 per cent was low, but it was attainable.

The target was comparable to other councils including the City of Bayswater target of 20 per cent canopy coverage by 2025, City of Fremantle’s 20 per cent by 2035, and Town of Vincent’s 20 per cent by 2050.

Mayor Irwin said volunteers were encouraged to sign up with the program and help with the planting process alongside Stirling staff members.

So far, one third of the canopy was on residential land.

Another benefit from having more trees was an increase in bee pollination, according to local bee expert Tristan Campbell.

“Without bees or pollinators in general, we won’t have most of the plants,” Mr Campbell said.

“Most of the oxygen is produced by angiosperms on land, so without pollination we’d lose a lot of oxygen as well.”

According to the Arbor Day Foundation, flowers found on trees were a critical source of food for the bees, providing pollen and nectar which was full of nutrients.

Prof. Imberger welcomed tree planting programs, saying the increased water production would make a big difference to the rising climate.

“An Australian timber tree will have roughly its own weight of water [expelled] every day of the year, so if a tree weighs ten tonnes it will pump out ten tonnes of water every day,” he said.

The Australian Bureau of Meteorology’s latest seasonal forecast predicted below average rainfall, with above average daytime temperatures.

A recent ABC News report found Denmark, 414km south-east of Perth and one of the wettest places in Western Australia, was running dry with below average rainfall, and may need to have water pumped from Albany in a process estimated to cost millions.

According to Prof. Imberger, the solutions were “so obvious, the only thing that stops things happening is the stupidity of politicians”.

The Amazon was subject to land clearing before the fires, so Brazil could have more farming land, in a movement backed by Brazil president Jair Bolsonaro.

American president Donald Trump pulled out of the Paris Agreement climate change initiative in 2017, saying it would undermine the US economy.

The Australian Government, led by Prime Minister Scott Morrison, had a strong commitment to the Paris Agreement, but still backed fossil fuels, recently approving a coal mine on the Queensland coast.

With people across the world demonstrating enthusiasm for solutions to our warming climate, Stirling’s Mayor Irwin said change could be enacted at a local level.

“I’m not sure what all the other local councils are doing but it’s certainly being addressed by many other local governments,” said Mayor Irwin.

“The obvious area that local governments can enact some regulation over is when development is happening on council property, so on our verges and in our public parks and in our recreation areas. That’s where it’s easier for us to actually do something”.

Just like the Amazon rainforest, where individual farmers caused significant damage to the environment, City of Stirling claimed the destruction of the urban canopy had not come from the removal of bushland, but from residents removing one tree at a time.

Mayor Irwin said Stirling council wanted to reverse that trend.

As Prof. Imberger said, “it’s time to get serious”.