Surabaya, Indonesia – Climate change, compounded by land-use changes, poses a growing threat to the biodiversity of Southeast Asia, and Surabaya, as a major city within this region, is not immune. A recent study published in Nature Climate Change has highlighted the severe risks faced by Southeast Asian forests due to these global shifts.
The study reveals that without a commitment to sustainable pathways, tree species and the ecosystem services they provide may be drastically diminished, leading to a range of environmental and social impacts. Surabaya, known for its urban greenery initiatives, particularly in the Bungkul Park and other green spaces, faces increasing pressure from both rising temperatures and urban expansion.
These trends, as noted in the Nature Climate Change study, are likely to exacerbate tree loss and degrade local ecosystems. The study emphasizes that Southeast Asia’s tree species are at risk of suffering severe losses in their distribution under various climate scenarios. Particularly, pathways involving intermediate climate change (SSP2–4.5 and SSP3–7.0) could lead to unexpectedly high biodiversity losses due to extensive land-use change.
“The climate in Surabaya is becoming less predictable,” says Nuurika, a student at Universitas Airlangga. “We’ve always had hot weather, but in recent years, extreme heatwaves are becoming more frequent. This is putting stress on our urban trees, which are essential for cooling the city and providing clean air.”
Urban trees in Surabaya play a critical role in regulating temperatures, reducing pollution, and supporting biodiversity. As one of the most populous cities in Indonesia, Surabaya has been recognized for its efforts to increase green spaces and reduce its carbon footprint. However, as the study warns, the combined effects of climate change and urban development could offset these gains.
The city’s trees are not only facing stress from rising temperatures but also from land-use changes as more green areas are repurposed for housing and infrastructure. The Nature Climate Change study modeled the distribution of 1,498 tree species under various global change scenarios, demonstrating that land-use changes, particularly in pathways like SSP2–4.5, could cause more severe losses in tree populations than even the worst climate change pathway (SSP5–8.5).
This is a warning for urban areas like Surabaya, where rapid development could outpace the city’s ability to mitigate the impacts on biodiversity. “The biggest concern is that these changes are happening so fast,” says Nuurika. “Our city is growing, and we need to balance that growth with environmental protection. If we lose our trees, we’re losing much more than just greenery—we’re losing the quality of life for all residents.”
To better understand the local impact of these global findings, we spoke with another university student, Maharani, a member of a local environmental organization. Maharani shared her concerns about the city’s vulnerability to climate change.“We are already seeing the effects,” Maharani explains.
“Heatwaves are becoming more intense, and there’s less rain during the dry season. Our green spaces are shrinking as new developments are built. This not only affects our environment but also the people who depend on these spaces for recreation and livelihood.” Maharani points to the vital role trees play in maintaining Surabaya’s livability.
“Trees cool our neighborhoods, reduce the urban heat island effect, and provide shade that makes life more bearable during hot months. But as the city grows, there’s more pressure to clear land for new buildings. If we don’t take action to protect our trees, the city will become much hotter and less hospitable.”
Maharani urges policymakers to prioritize sustainable development, echoing the findings of the Nature Climate Change study that recommends a focus on pathways like SSP1–2.6, which promotes sustainability and mitigates both climate change and land-use impacts. “We need to act now,” Maharani says.
