The loss of our urban green spaces may cost us more than we think

As inner-city areas, like West End, grapple with a growing population and a finite amount of space to fit in, community concern about the loss of our green spaces is mounting.

As various new forms of public infrastructure are needed to cater for population growth, the result is often removal of green assets to generate the necessary space.

I recently embarked on a journey to understand the current process for offsetting these environmental losses – you can read more about what I found here.

Can’t see the forest for the trees: Does environmental offsetting work?

This journey led me to Urban and Environmental Planner, Dr Tony Matthews, who shared with me the benefits of our urban green spaces.

During our conversation, it became clear the scope of benefits extends far beyond the simple enjoyment of a picnic in the park, or a pleasant walk home from the bus stop.

Social and physical benefits

Dr Matthews said there are numerous social and physical benefits associated with regular exposure to green space.

“If you spend more time in nature or natural settings, it’s going to likely have positive benefits for your physical health,” he said.

He said there are proven, demonstrable benefits that indicate good quality and accessible green space relieves stress and anxiety.

“So that can be during the workday, or any time really, but if you’ve managed to get out of the office for half an hour at lunchtime and sit in a park, chances are you’ll come back feeling much better, and people tend to gravitate towards green space for those sorts of restorative benefits,” he said.

He told me that, on average, sustained exposure to green space can have other positive health benefits, like reducing blood pressure which, over time, can reduce the risk of disease and early death.

On a community level, Dr Matthews said green space fosters active and participatory living.

“That’s where people are participating that community, they’re out and around the place. They’re meeting their neighbours, engaging with the local economy, playing with their kids, they’ve got a paint easel set up where they’re painting landscapes. Anything like that, that’s all what we call active living,” he explained.

He went on to explain that a key difference in the way green space fosters active living is that it’s free to use.

“You could say, my local cafe fosters active living every Saturday morning. It’s the busiest place in town. This might be true but you have to pay to go there, and with greenspace you don’t. So, it’s fundamentally different. It acts differently because of that and people respond to that differently.”

Another positive side effect of active living is that it encourages social interaction.

He said if you are engaging in pleasurable, relaxing activities in an environment that reduces stress, surrounded by people in your community, chances are you will be more socially interactive.

“It also gives people a focus for their social interaction. Elderly people might go there because it’s got nice walking paths and good shading, parents might meet each other because they bring their children there at the same time every week,” he said.

A particularly interesting finding, according to Dr Matthews, is that green spaces tend to reduce anti-social behaviour, crime, and instability.

“The common thought on green spaces is, if you’ve got more green space, you’ve got more trees and hedges and things like that then there’s obviously more places for people to lurk and get up to bad things because it reduces sight lines and so on,” he said.

“But actually, most of the research – and particularly this is North American research – points to the fact that overall the presence of decent greenspace moderates incivility, so it actually reduces crime and antisocial behaviour, it doesn’t encourage it. That’s very beneficial on a community level.”

 

Environmental Benefits

According to Dr Matthews, urban green space can reduce noise and lower wind speeds, resulting in a more comfortable environment for an area’s inhabitants, in addition to what is perhaps the most well understood environmental benefit of green space: its ability to sequester carbon.

“Trees, grass, shrubs, anything really that’s living will absorb some carbon out of the atmosphere and that’s obviously beneficial,” Dr Matthews said.

“In turn that will reduce localised air pollution, or will reduce some forms of pollutants from the air. It doesn’t mean that it will completely clean the air, but it will reduce a certain amount of pollutants from the air. That’s one of the reasons that the air is so good in Brisbane, because we have so much greenery.”

He said green space also has the ability to augment habitats.

“It improves biodiversity and improves habitat potential for species. It can lead to new species arriving or – depending on the volume and quality of your green space – it might provide a good enough basis for a local koala population to survive, or bird populations, mammals, anything like that. So, again, it’s a really good opportunity to enhance habitats, or safeguard them, if you can protect green space,” he said.

“A big one in the environmental sense, is reducing ambient temperatures. Excessive heat also affects ecosystems, as well as people, and effects natural systems and all the creatures that inhabit them,” he said.

With regard to the cooling benefits of urban green space, Chair of Treenet, Dr Lyndal Plant, said urban green space and tree canopy cover can offset the urban heat island (UHI) effect.

The UHI effect results from hard, dense surfaces like bitumen roads and concrete buildings naturally absorbing heat, and also radiating it during the evening.

Dr Plant said greenery, including trees and grass, can help to cool our urban areas and decrease reliance on things like air conditioning.

“The value of vegetation towards cooling and energy saving benefits, plus the human health benefits, [is something] that we should not lose sight of as that is something that is incredibly important for inner suburb areas,” she said.

Economic benefits

Dr Matthews said the flow-on effect of this cooling effect leads to a major economic benefit: decreasing health care expenses.

He said heat stress is a major health issue across the whole of Australia.

“Heat stress is the one that causes the most problems, costs the most, and is the hardest to deal with, and kills the most people,” he said.

“Way more people suffer death and injury from heat than they do from anything else.”

He said decent quality green space can be used to reduce the heat burden in certain areas.

“If you can use green infrastructure to reduce that heat burden, then that reduces people’s tendency to get sick from excess heat, or worse to die from it. So that reduces health care expenses overall,” he explained.

His own research found that during heat waves the number of ambulance call outs can quadruple as a result of people suffering from heat stress.

“So you think about the enormous burden that then places on the health system, and then the health system has to bring in extra doctors and nurses and pay them over time. There’s huge costs associated with those kinds of things,” he said.

“So it is actually a way of reducing healthcare expenses from the individual level right up to the state level, and up to the Queensland Health level.”

“Unfortunately, that’s not really well understood by health systems, or they don’t see this as an opportunity, or it just doesn’t really figure into their thinking yet.”

He also mentioned that due to many confounding factors, it is difficult to empirically establish how much the health care system would save if green space were expanded.

In addition to these benefits, he said green space can reduce stormwater costs and increase property values.

My conversation with Dr Matthews left me wondering why so much of our valuable green space is being removed to make way for new developments, and how much will this cost us in the long term?