More than 300 people - participants and organisers of an event at Suntec City Convention Centre - took out their phones at the start to make a pledge together.
They promised to work towards goals such as making a commitment to recycle, using energyefficient devices and conserving water, so as to reduce their carbon footprints.
This took the number of individuals, schools and organisations who have signed the climate action pledge launched in January by Minister for the Environment and Water Resources Masagos Zulkifli, to more than 303,300.
Among those who signed the pledge at the RHT Asean Summit 2018 yesterday was Dr Amy Khor, Senior Minister of State for the Environment and Water Resources, who also delivered the keynote address.
The event organised by law firm RHTLaw Taylor Wessing was attended by more than 200 people, including business leaders, industry experts and professionals, and ambassadors from Asean nations.
South-east Asia is one of the most vulnerable regions to natural disasters and climate change, said Dr Khor, who urged those present to work towards strengthening the region's environmental resilience.
She said: "The impact of these climate-related disasters is magnified in today's interconnected world and can affect economies and societies beyond national boundaries.
"We are working with fellow Asean countries to ensure that Asean remains resilient and united against increasing environmental risks, while transforming our economies to be more innovative and future-ready."
Additionally, she said there were several platforms to open up new opportunities for sustainable growth in the region. These include the Asean Smart Cities Network for South-east Asian countries to collaborate and tackle urban challenges with digital solutions.
Dr Khor mentioned a new office, Infrastructure Asia, which will try to connect local and global stakeholders across the value chain, generating more opportunities for infrastructure projects in the region.
In her speech, she noted several trends, including the shift towards a low-carbon future, the growing call for sustainable production and consumption, as well as an increase in the traction of green finance both globally and regionally.
Green financing refers to the increasing financial flows from the public, private and not-for-profit sectors to sustainable development priorities, according to the United Nations Environment Programme.
Dr Khor also cited the shift to the circular economy as a way of allowing finite resources to be used for as long as possible, combating the supply chain vulnerabilities of the current linear economy model of "make, use and dispose".
"This requires a fundamental change in perspective, where materials at a product's 'end of life' are not considered waste, but a valuable resource," she said.
As the chair of Asean and the coordinator for Asean-EU relations, Singapore will work with Asean countries and the group's dialogue partners to strengthen regional cooperation on the circular economy, she added.
•To support the #CLIMATESG climate action pledge, go to http://mewr.gov.sg/individual-pledge