Environment · Cities · Inequality

In Sydney, the trees follow the money. Wealthier suburbs sit under a thick green canopy that cools the air on extreme-heat days; poorer suburbs bake in the open. As heatwaves intensify, an unequal map of shade is quietly becoming an unequal map of who stays safe.

Tree canopy is not decoration. Shade and the moisture trees release can leave a leafy street several degrees cooler than a bare one on a hot day — and extreme heat is Australia’s deadliest natural hazard. Using NSW Government canopy data for 605 Sydney suburbs joined to ABS socio-economic data, these five charts trace how greenery, wealth and heat exposure line up.

1. A city of haves and have-nots

The leafiest Sydney suburbs sit above 50% canopy cover. The barest — many of them new estates built on cleared paddocks — have almost none.

Top and bottom 10 of 605 suburbs. Green = leafiest, red = barest. Source: NSW DPHI (2024); ABS (2023). Hover for detail.

2. The trees follow the money

Plot every suburb’s canopy against its socio-economic advantage and the pattern is unmistakable: greener suburbs are wealthier suburbs (correlation r = 0.43). Each dot is a suburb; larger dots hold more people.

Each point is a suburb; size = usual resident population; colour = socio-economic group. Dotted line = linear trend. Source: NSW DPHI (2024); ABS (2023).

3. Who lives in the heat-exposed suburbs?

Because canopy tracks wealth, the people in the barest — and therefore hottest — suburbs are disproportionately those least able to cope with extreme heat. This chart counts residents by how much canopy their suburb has.

Residents grouped by their suburb’s canopy band and socio-economic group. Shade lowers local temperatures through shading and evapotranspiration (NSW DPHI, 2024). Source: NSW DPHI (2024); ABS (2023).

4. The divide, council by council

Zoom out from suburbs to whole councils and the same split appears. Sydney’s leafiest councils are among its most advantaged; the barest are among its most disadvantaged.

Each dot is a Greater Sydney council; colour = socio-economic group; hover for population. Source: NSW DPHI (2024); ABS (2023).

5. Is the gap closing?

Some good news. Between 2019 and 2022 — as NSW greening programs targeted the hottest, barest areas — disadvantaged and middle suburbs gained canopy, while advantaged suburbs flat-lined. The divide is still vast, but it has begun to narrow.

Mean canopy per socio-economic group. Note: 2019 and 2022 were captured with slightly different methods, so treat change as indicative (NSW DPHI, 2024). Source: NSW DPHI (2024); ABS (2023).

References

Australian Bureau of Statistics. (2023). Socio-Economic Indexes for Areas (SEIFA), Australia, 2021 [Data set]. https://www.abs.gov.au/statistics/people/people-and-communities/socio-economic-indexes-areas-seifa-australia/latest-release

NSW Department of Planning, Housing and Infrastructure. (2024). Greater Sydney Region Tree Canopy 2022 [Data set]. SEED. https://datasets.seed.nsw.gov.au/dataset/greater-sydney-region-tree-canopy-2022

Acknowledgement of GenAI use. The author used Anthropic’s Claude to assist with R code structure, data-join troubleshooting and narrative framing. All data analysis, design decisions and final code were reviewed and verified by the author. Anthropic. (2025). Claude [Large language model]. https://claude.ai