Across Southeast Asia, the push for more sustainable and resilient cities is increasingly moving from policy discussions towards practical action. At the SEA Youth Summit interactive roundtable, titled “Building Sustainable Cities: From Policy to Practice,” young delegates from Indonesia, Malaysia and Timor-Leste brought forward ideas addressing some of the region’s most pressing environmental challenges, from waste management and urban flooding to circular economies and renewable energy.

Their proposals highlighted the importance of turning local solutions into scalable initiatives, while strengthening regional cooperation and giving youth a more active role in shaping the future of their communities.

Indonesia: Beyond waste-to-energy

The session opened with Musawwir Muhtar from Indonesia, who said the country recognised solid waste management as an urgent national issue, with only about one-third of its waste currently being managed properly. He argued that regulations alone were no longer sufficient, calling for greater investment and immediate action to address the country’s growing waste crisis.

As part of its response, Indonesia is committing US$5 billion through a joint-venture partnership with Danantara, the country’s sovereign wealth fund, to develop waste-to-energy facilities.

However, he said that waste-to-energy should not be treated as the country’s sole solution, warning that such facilities could create a reliance on a constant supply of waste. Instead, Indonesia needed to combine waste-to-energy with better waste sorting, recycling, waste reduction and collection infrastructure. Musawwir said the goal should be to reduce waste at source while safely managing what remains.

Malaysia calls for ASEAN flood resilience “Twin Labs”

Representing Malaysia, Lavine See Yu Tian called for ASEAN Flood Resilience Twin Labs to test and validate nature-based solutions (NBS) for urban flooding, an approach that earned her the Best Speaker award.

She said heavier rainfall, rapid urbanisation and the loss of natural ecosystems were worsening flood risks across ASEAN, while solutions such as rain gardens, wetlands and bioswales remained underused despite their potential to reduce runoff and improve water retention.

Under the proposal, cities such as Klang and Jakarta could implement similar NBS projects using a common ASEAN framework to measure outcomes such as infiltration rates and maintenance costs. Local governments, communities and private-sector partners would support implementation, with universities independently validating the results.

If successful, the projects would enter an ASEAN replication track, allowing other cities facing similar flood risks to adopt proven designs instead of starting from scratch. The approach would shift ASEAN cooperation from a cycle of “pilot, report and stop” towards one of test, validate, replicate and scale, with the potential to restore wetlands, reduce pressure on drainage systems and strengthen flood resilience across the region. The speaker said ASEAN did not lack ideas, but needed a stronger mechanism to turn local successes into regional action.

Timor-Leste calls for a circular waste system

Representing Timor-Leste, Lilyana Da Cruz highlighted the growing pressure that urbanisation and rising waste generation are placing on the country’s environment and communities. She said poor waste management, particularly plastic waste, could clog drainage systems during heavy rainfall and carry waste into coastal areas, increasing flood risks while affecting public health and community well-being

She called for a shift from disposal towards a circular, community-based waste management system focused on reducing, reusing, recycling and recovering waste. This would involve improving waste collection and segregation, expanding recycling and reuse, strengthening public education and creating opportunities for the green economy.

Building on her proposal, Lilyana proposed an ASEAN Youth Circular Community Initiative to connect young people, local governments, universities, businesses and communities in developing practical solutions to local waste challenges. Participating communities would identify priorities, develop and test solutions, measure their results and share successful approaches across the region.

UNDP urges more youth-led environmental proposals

Siti Salwa Samsudin, SGP National Coordinator at UNDP, highlighted the need to encourage more youth-led proposals, noting that the programme has technical experts who can help young people develop and strengthen their ideas into viable projects.

“We do not have many proposals coming from youth. So, what we can do is support and build up your proposals. We have technical experts who can guide you.”

Building on more than 26 years of implementation in Malaysia, the Small Grants Programme (SGP) continues to support community-led initiatives that deliver global environmental benefits while strengthening local livelihoods.

She also said the SGP operates in other countries too, giving communities and organisations opportunities to learn from experiences and solutions beyond Malaysia.


Youth engagement is key to shaping sustainable solutions

Drawing on her experience at SAP, where she has seen how technology, software and innovation can contribute to sustainability projects with real-world impact, Carola Tiefenthaler, Principal Enterprise Architect at SAP based in the APAC region, said she wanted to bring that perspective to students and challenge them to think about the role they could play in creating a more sustainable future.

“What made the session particularly meaningful, however, was the engagement from the students themselves. Bringing together young people from across Southeast Asia, the room was filled with participants who were genuinely curious and unafraid to ask difficult and relevant questions about sustainability, technology and the challenges facing the region,” she said

Energy security and sustainability through innovation

Roland Rudorfer, Deputy Head of Mission at the Austrian Embassy in Malaysia, shared Austria’s experience in using renewable energy and technological innovation to strengthen sustainability and energy security.

He highlighted how Austria’s electricity generation relies primarily on hydropower, wind power, biomass and solar energy, which produce little to no greenhouse gas emissions while reducing the country’s dependence on energy imports and strengthening security of supply.

His sharing added an international perspective to the debate, showing how lessons from Austria’s sustainability efforts could offer ideas for Southeast Asian countries as they consider how to balance environmental goals, energy needs, and long-term resilience.

As Southeast Asia continues to urbanise, the challenge will be to ensure that promising ideas do not stop at the pilot stage. By connecting communities, governments, businesses, universities and young innovators, the region can build on what works, learn from one another and create cities that are not only greener, but more resilient and inclusive for generations to come.