• Pouring concrete when rebuilding parks - is the rebuilding of whole parks too polluting compared to renovating them?
Kyle Day, an intern with Sustainable House and visiting from the city of Chicago in the U.S. investigates and quantifies the pollution from rebuilding 68 city parks in Sydney by 2032.
Kyle introduces himself
Understanding the Environmental Impact of Sydney's Park Reconstructions
The City of Sydney has recently started on an ambitious plan to renovate 68 local parks, “aiming to create vibrant and sustainable spaces for the community”. However, there is a significant issue that is undisclosed. The construction of rebuilding these parks causes a huge amount of pollution, which is untracked and unreported.
In this blog, we delve into the environmental impact of these reconstruction projects and explore the importance of transparency in addressing the pollution they’re causing through to 2032.
The council has not estimated the anticipated climate pollution from rebuilding the 68 parks or any one of them. The rebuilding for the 68 parks is one project and the individual and cumulative climate impact is not counted or disclosed by the council.
Let’s look at one of the projects presently under construction, Peace Park, in Chippendale.
• Council’s website says its ‘upgrading Peace Park’
A letter drop to Chippendale residents dated 4 January 2023 said the park rebuilding project was targeted “for completion by the end of April 2023.”
• The park rebuilding project was targeted “for completion by the end of April 2023.”
At the date of writing this blog, 26 June 2023, almost six months since it started the project is still under construction.
UnraveLling the Environmental Impact
Construction sites contribute significantly to climate pollution, primarily through the emission of greenhouse gasses (GHGs). Some alarming statistics for construction site pollution:
1. Energy Consumption:
Construction sites are energy-intensive environments, often relying on fossil fuels. According to a study by the International Energy Agency (IEA), the construction sector accounts for nearly 36% of global final energy use and approximately 40% of total energy-related CO2 emissions.
2. CO2 Emissions:
The construction industry is responsible for a substantial portion of global CO2 emissions. Estimates suggest that construction activities contribute to approximately 23% of total global CO2 emissions. This includes both direct emissions from on-site machinery and indirect emissions from the production of construction materials.
• A lot of stuff being stored, coming and going beside the park and taking over the two car spaces used by a car-sharing company to reduce car ownership and use
To gain a better understanding of the environmental impact, let’s examine the estimated CO2 emissions for the equipment used in the reconstruction of Peace Park in Chippendale.
I met with the manager of a park reconstruction site that is comparable to the ones proposed in the council’s new parks rebuilding plan. The manager gave me a better understanding of the equipment used in the rebuilding process. I created the following graphic after our meeting:
Climate Pollution for a Typical Park Over 6 Months
• Some of the equipment used to rebuild parks
• There’a a lot of energy-hungry equipment used to rebuild and to renovate parks
In the calculations above the Total Low/High Estimates over the entire duration of construction (highlighted in green) were calculated using the following formula:
Weekly Use(hours) * Low/High Estimate(kg CO2e/hour) * Number of weeks
• About 20 or so workers on site for over 22 weeks
To get the total pollution we also need to count the emissions from making the cement and the pollution from all of the workers commuting to work into consideration.
There is a significant amount of CO2 emissions coming from these materials and transport to and from work, so it is essential that they are included in the total estimate for the park.
• A cement factory
According to the International Energy Agency (IEA), the global average CO2 emissions intensity for cement production is around 0.6-0.7 metric tons of CO2 per metric ton of cement produced .
Therefore, for a plant producing 10-30 tons of cement, we can estimate the CO2 emissions as follows:
Low Estimate: 10 tons * 0.6 tons CO2/ton = 6 tons of CO2 emissions
High Estimate: 30 tons * 0.7 tons CO2/ton = 21 tons of CO2 emissions
• One of the typically two front end vehicles on Peace Park for over 22 weeks
Additionally, the CO2 emissions from all of the construction workers commuting to work can be estimated.
l assumed an average of 20 workers will be at the site on any given day. Most of these are men who drive separate cars into work everyday and have an estimated 1 hour commute each way. This means the construction site needs a combined total of 40 driving hours each day, so 200 hours a week. The park reconstruction has taken over 22 weeks so far, meaning approximately 4,400 hours of driving were needed to bring the men into work.
To calculate the total CO2 emissions for 4,400 hours of driving, we need to know the fuel consumption rate of the vehicle and the type of fuel used. Let's assume a fuel consumption rate of 10 litres per hour for this example and that the car is powered by gasoline.
CO2 emissions per hour = Fuel consumption rate (in liters/hour) * CO2 emissions per liter
CO2 emissions per hour = 10 liters/hour * 2,310 grams CO2/liter = 23,100 grams (or 23.1 kg) of CO2 emissions per hour
Total CO2 emissions for 4,400 hours = CO2 emissions per hour * 4,400 hours
Total CO2 emissions = 23.1 kg/hour * 4,400 hours = 101,640 kg (or 101.64 metric tons) of CO2 emissions
Based on the table estimating the pollution that comes from a single park reconstruction, we can calculate the total CO2 pollution for the park by multiplying the columns in green by the total number of each item and then summing all of those values:
Low Estimate Total CO2 Pollution: 23,984.8 kg CO2
High Estimate Total CO2 Pollution: 38,872 kg CO2
These figures provide an approximate range of the CO2 pollution resulting from the construction of the parks being rebuilt; 68 new parks are scheduled to be rebuilt. Extrapolating these estimates to all 68 parks being rebuilt, we can anticipate the potential total CO2 pollution for all the parks combined.
By adding this estimate with the additional emissions estimates from the cement manufacturing and commuting time of workers, we get:]
a total low estimate of 131,624.8 kg CO2 pollution and
a total high estimate of 161,512 kg CO2 emitted for the reconstruction of one park.
Using these estimates, we can finally calculate how much pollution all 68 parks will create:
Low Final Estimate CO2 Pollution: 131,624.8 * 68 = 8,950,486.4 kg CO2
High Final Estimate CO2 Pollution: 161,512 * 68 = 10,982,816 kg CO2
There is about 9,000 to 11,000 tons of CO2 pollution set to be created in the reconstruction of all 68 parks.
That is a lot of pollution!
For comparison, the average American household produces around 8 tons of CO2 emissions per year.
The rebuilding of just one of these 68 parks is the equivalent to the total annual carbon emissions of 18 seperate U.S. households.
The total pollution from reconstructing all 68 of these parks is comparable to the CO2 emissions from around 1,300 separate homes.
Comparing the parks construction pollution estimates to motor vehicle emissions, building one park is equivalent to the pollution created from the total annual use of 33 different cars (https://www.epa.gov/greenvehicles/tailpipe-greenhouse-gas-emissions-typical-passenger-vehicle). The reconstruction of the entire 68 parks is the same as the carbon emissions from the annual usage of 2,173 separate cars.
• The council’s “Green Plan” doesn’t count its greenhouse climate pollution
None of this pollution is being accounted for by the City of Sydney council.
• Sydney City Council’s draft budget for the year ending 2024 shows it proposes $572.6m to rebuild 68 parks by 2032, p81
Sydney City Council’s draft budget for the year ending 2024 shows the council proposes $572.6m to rebuild 68 parks by 2032.
That’s a lot of money on rebuilding parks over the next ten years.
I ran a search in the councils’ Green Plan for terms like carbon, emissions, CO2, pollution, etc. and less than 30 matches came up within the nearly 300 page long document. On the pages that did contain these terms, there was no detail as to how things like CO2 emissions would be quantified.
This image above from The Green Plan demonstrates that the city claims to want to reduce climate change, but has no quantifiable plan to do so. Words like “manage emissions” are vague and aren’t actionable.
Is a total rebuild needed or just some renovation?
Given the huge environmental impact and pollution generated by these park reconstructions, I suggest we citizens need to ask - is rebuilding these parks necessary?
Could alternative approaches be used to preserve the existing parks while still meeting the community's needs?
By re-evaluating why these parks need to be fully rebult, we can potentially reduce the carbon pollution associated with these projects and explore more sustainable alternatives.
In the Project Scope document for the proposed reconstruction of Peace Park, the reasoning for the upgrade is as follows,
“The key principles of the proposal are to upgrade the turf surface, renew the playground to provide a local scale play space which maximises play opportunities for children of different ages and abilities, improve access in and around the park, improve lighting and use simple, robust, high quality materials which reflect the local neighbourhood character.”
Based on the large amounts of pollution that went into the making of the park, we have to consider whether the new changes to “upgrade turf surface” and “improve lighting” are both an accurate description of the works actually carried out and whether they are worth the environmental repercussions.
Conclusion
As the council embarks on the ambitious journey to rebuild its local parks during what the council has formally declared is a ‘climate emergency’, it is crucial for the council and community to count the hidden environmental impact of these construction projects.
The untracked and unreported pollution resulting from these reconstructions is harming our environment in a big way. By questioning the necessity of rebuilding the parks and exploring alternative approaches, we can strive for a greener and more sustainable future for our city.
Kyle Day,
Intern with Sustainable House