One street tree can boost Sydney house prices by $30,000 – or cost $70,000 if it’s too close: new study

A single street tree can potentially increase an average Sydney house price by A$30,000, our new research shows. This echoes past research showing street trees not only help boost property prices, but offer other benefits, from improved scenery and privacy to increased shade.

But there’s a catch. Our analysis, published in the international Cities journal, also found that if a street tree is too close, it can actually reduce the selling price by more than $70,000.

Our study looked at more than 1,500 house sales in the City of Sydney from 2021 to 2024, then matched those with detailed council data on nearly 50,000 public trees.

After accounting for other, better known price factors – number of bedrooms, bathrooms, car parking, land size, proximity to the CBD, transport, schools and more – we found trees can be associated with higher house prices. But that price boost only occurred when the trees were about 10–20 metres from a home, such as across the street or near the frontage.

In contrast, trees planted too close – within a 10m radius from the centre of the property – were actually associated with lower sale prices.

This matters beyond Sydney. Every Australian capital city has set tree-planting goals, such as the City of Sydney’s target for 23% tree canopy cover in 2030 and 27% in 2050. Yet many will struggle to meet them, with some facing resistance from residents. Our research explains why tree placement will be crucial if we ever want to meet those targets.

What’s new about this research

Past studies in Perth, as well as several cities in the United States and Canada, have consistently shown trees tend to increase property values.

But what we didn’t know before now was where the benefits stop and the costs begin.

Our study identifies a clear “not in my backyard” (NIMBY) boundary, of around 10m, within which street trees’ economic value turns negative.

That finding is important, because that’s when resident resistance to street trees is likely to be strongest.

This is a first study of its kind to quantify the economic value of public trees by taking advantage of using individual tree-level data managed by the City of Sydney from 2023.

It allowed us to measure tree effects at the finest possible distance from the centre of property: under 10m, 10–20m, 20–50m, 50–100m, and beyond 100m. This is something previous studies could not do when relying on satellite or street imagery.

How tree location affects price

We controlled for all the usual factors that influence house prices, including property features and location amenities. This meant we could measure the impact of trees after accounting for everything else.

We found that distance matters. In dollar terms, one additional tree within 10m of the centre of a property reduced its value by 2.96%. An average home sold in the City of Sydney from 2021 to 2024 was worth $2,613,000 – so that reduction worked out to be a $70,290 cost.

Given the average lot size of 176m² in the City of Sydney, the distance from the centre of an average property to its boundary is typically about 8m.

But if a tree was located 10-20 metres away, it increased the value by about 1.16%, worth an average of $30,310.

If the tree was further than 20 metres away, we found no price difference.

The new study identified a clear ‘not in my backyard’ (NIMBY) boundary, within which street trees’ can actually hit house prices. Belle Co/Pexels, CC BY

This show a clear proximity effect. Trees being too close to a house are a cost risk; trees at a moderate distance are a valued feature; and trees further away are neutral and just part of the neighbourhood amenity.

Our study used more precise data than ever before to calculate the distance between street trees and the centre of each property.

But future research could take this further by measuring the distance from each tree to the house. It could also incorporate resident surveys to better understand how people perceive and value trees near their homes.

Why trees being too close matters

Street trees like these are much loved – but can have hidden downsides, such as damage from roots or branches. Jo Quinn/Unsplash, CC BY

It makes sense that people may see trees close to home as a financial risk.

Trees can cause structural damage to buildings and infrastructure, increase fire hazards, and safety concerns from falling branches.

Rather than dismissing residents’ concerns as NIMBYism, they should be seen as rational market responses to maintenance risks, structural damage, and amenity loss.

Planting plans need resident support

Every Australian capital city has adopted “urban forest” or tree planting strategies, many of them aiming to hit 30-40% canopy cover in coming decades. For example, the City of Melbourne’s target is 40% canopy cover by 2040, while Brisbane City Council is aiming for 50% shade for residential footpaths and bikeways by 2031.

However, there are doubts about whether many of those targets will be met.

There are good reasons for governments to invest in urban trees, as they can protect us from extreme heat and help as a response to climate change. But resistance from homeowners can undermine these policies.

Our research shows residents are more likely to welcome street trees if they’re planted not too close, and not too far, from their homes.

* Thanks to the coauthors of this paper, Qiulin Ke and Bin Chi from University College London.The Conversation

Song Shi, Associate Professor, Property Economics, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Study Shows Vaporizing E-Waste Makes it Easy to Recover Precious Metals at 13-Times Lower Costs

credit Alexandre Debiève

By instantaneously heating electronics to 3,000°C via an electrical current, scientists have found a way to extract decent grades of precious metals without creating hazardous waste.

According to their analysis, relying on e-waste for a precious metals supply could be 13-times cheaper than mining them from the ground. However, previous methods have involved throwing this or that broken gizmo into a furnace powered by copious amounts of energy while also releasing toxic substances into air.

By contrast, “flash joule heating,” a way of using electrical currents to vaporizing the valuable metals from the materials that hold electronics together is between 80 and 500-times more energy efficient.

One 2008 study calculated that one ton of mobile phones without batteries contains about 130kg of copper, 3.5kg of silver, 340 grams of gold, and 140 grams of palladium.

Those totals, if assayed as part of a drilling survey at a mine, would be considered world class results in the 99th percentile of grades.

Most open pit mining operations will run at a rate of between 0.5 and 1.8 grams per-ton gold and 100 to 180 grams per-ton silver. Some 40 million tons of e-waste is produced annually, so some simple mathematics reveals the potential economy to be found in harvesting e-waste for metals—a process termed “urban mining” by scientists.

Scientists at Rice University shredded a printed circuit board for their experiments, and mixed it with carbon black as a conductive additive. Once in the flash joule chamber, the current applied is so high that the precious metals, like rhodium, copper, and gold, turn briefly to vapor, while the carbon-based components like the plastic, are carbonized. This same process has been used to turn plastic into diamonds.

Mining companies for base and precious metals use a variety of patented recovery processes to separate gold, zinc, or nickel from the ore body.

Just like in mining, additives enhanced the recovery percentage of the metals from their vaporized form, including halides or fluorine-based substances. These brought the recovery of rhodium up to greater than 80%, and palladium to 70%. Bleach and other chlorine-based compounds brought the silver recovery rate up to greater than 80% as well.With the prices of these metals skyrocketing of late, new and cheaper supplies will be crucial to ensure important industries remain intact and competitive. Study Shows Vaporizing E-Waste Makes it Easy to Recover Precious Metals at 13-Times Lower Costs
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World's richest 10% caused two thirds of global warming: study


The world's wealthiest 10 percent of individuals are responsible for two thirds of global warming since 1990, researchers said on Wednesday.

How the rich consume and invest has substantially increased the risk of deadly heatwaves and drought, they reported in the first study to quantify the impact of concentrated private wealth on extreme climate events.

"We link the carbon footprints of the wealthiest individuals directly to real-world climate impacts," lead author Sarah Schoengart, a scientist at ETH Zurich, told AFP.

"It's a shift from carbon accounting toward climate accountability."

Compared to the global average, for example, the richest one percent contributed 26 times more to once-a-century heatwaves, and 17 times more to droughts in the Amazon, according to the findings, published in Nature Climate Change.

Emissions from the wealthiest 10 percent in China and the United States which together account for nearly half of global carbon pollution each led to a two-to-threefold rise in heat extremes.

Burning fossil fuels and deforestation have heated Earth's average surface by 1.3 degrees Celsius, mostly during the last 30 years.

Schoengart and colleagues combined economic data and climate simulations to trace emissions from different global income groups and assess their impact on specific types of climate-enhance extreme weather.

The researchers also emphasised the role of emissions embedded in financial investment rather than just lifestyle and personal consumption.

"Climate action that doesn't address the outsized responsibilities of the wealthiest members of society risk missing one of the most powerful levers we have to reduce future harm," said senior author Carl-Friedrich Schleussner, head of the Integrated Climate Impacts Research Group at the International Institute for Applied Systems Analysis near Vienna.

- Billionaires tax -

Owners of capital, he noted, could be held accountable for climate impacts through progressive taxes on wealth and carbon-intensive investments.

Earlier research has shown that taxing asset-related emissions is more equitable than broad carbon taxes, which tend to burden those on lower incomes.

Recent initiatives to increase taxes on the super-rich and multinationals have mostly stalled, especially since Donald Trump regained the White House.

Last year, Brazil -- as host of the G20 -- pushed for a two-percent tax on the net worth of individuals with more than $1 billion in assets.

Although G20 leaders agreed to "engage cooperatively to ensure that ultra-high-net-worth individuals are effectively taxed," there has been no follow-up to date.

In 2021, nearly 140 countries agreed on work toward a global corporate tax for multinational companies, with nearly half endorsing a minimum rate of 15 percent, but those talks have stalled as well.

Almost a third of the world's billionaires are from the United States more than China, India and Germany combined, according to Forbes magazine.

According to anti-poverty NGO Oxfam, the richest 1 percent have accumulated $42 trillion in new wealth over the past decade.

It says the richest one percent have more wealth than the lowest 95 percent combined.

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