Leaders of the world’s biggest cities gathered in South Africa Tuesday for the C40 Mayors Summit and discussions focus on sustainability and urban solutions to climate change.

 

The Summit will provide a forum for global leaders to share best practice and deliberate on how cities can become energy efficient and boost climate change adaptation and mitigation methods.

 

The three-day summit, launched Tuesday in Johannesburg, is the fifth biennial meeting and is the first time it has been convened in Africa.

 

Former New York mayor Michael Bloomberg is the C40 Cities chairperson and said cities "account for 70 per cent of the world's carbon emissions, a figure that'll rise if nothing is done because the total population of the world's cities is going to double by 2050.”

 

UN Secretary General Ban Ki-moon appointed Bloomberg as the UN special envoy for cities and climate change last week and it is hoped he can spearhead a new wave of action on the issue.

 

The C40 Cities Climate Leadership Group was created in 2005 by former London mayor Ken Livingstone to help the leaders share policy and technological innovations.

 

It began as a coalition of 18 megacities and has now expanded to include 58 cities across five continents representing 1 in 12 people worldwide.

 

Christiana Figueres, the UN climate chief, attended this year’s summit, and delivered a keynote speech on Wednesday.