Hollywood star Leonardo DiCaprio has championed the importance of sustainable cities in the global battle against climate change.

Today (22 April) 130 countries will sign the landmark agreement reached in Paris last December to tackle global warming. Reflecting on this breakthrough in the Guardian newspaper, DiCaprio cautioned that it is “just the beginning” in the drive to avoid “the catastrophic impacts” of rising temperatures.

The Oscar winning actor outlined five principles to limit climate change further: reducing and pricing carbon emissions, accelerating the transition to renewable energy, protecting vital ecosystems, taking aggressive short-term action and making our cities global models for sustainability.

“Over half the world’s population lives in dense urban areas that generate more than 70 per cent of global emissions,” he wrote. “Any long-term changes must involve major cities from both hemispheres. Already, many are serving as models. Vancouver, Sydney, Stockholm, and Las Vegas have already committed to using 100 per cent renewable energy in the coming decades. Other cities must follow their lead.

“These are real solutions, many of which are already being implemented in parts of the world to great success. It is up to political and community leaders, businesses, and citizens everywhere to act as guardians not just of this new, aggressive set of standards for climate action – but as guardians of our future.”

DiCaprio added we must safeguard our forests and oceans, reward innovators and entrepreneurs who develop and deploy cleaner technologies, and invest in renewable energy to “usher in a new era of economic promise and security for people around the world.”

“We know what needs to be done,” he wrote, “and together, we must stand up and fight for these meaningful, effective solutions. Failing to do so will unjustly leave our children a world that is hotter, less diverse and more violent and unjust – all things we can avoid with bold action now.”

DiCaprio is famous for his environmental campaigning and is a longstanding supporter of sustainable design. He is currently developing an eco-resort on his private island in Belize in partnership with wellness real estate firm Delos and architects McLennan Design.

Leisure architects, designers and investors around the world are increasingly focusing on sustainable design at city scale.

Atelier Ten environmental design consultant Patrick Bellew recently told CLAD that the competitive nature of property developers has benefitted the sustainability of buildings, with rival firms fighting to be “the greenest, the biggest and the best.”

Recently unveiled innovative ideas from architects include tree-covered towers, non-chemical desalination technologyn, ‘edible’ gardens at sports stadiums and the comprehensive planting of plants and greenery in disused parts of cities.

US president Barack Obama, who has made tackling climate change a key goal of his time in office, has promoted the advancement of liveable cities by proposing higher taxes on oil firms and more funding for green transportation projects.