Cities are home to more than half the world’s population and account for some 70 per cent of global emissions, making them crucial in the global effort to tackle climate change. A UN study in July projected that urbanisation - combined with population growth - could add another 2.5 billion people to cities by 2050, with close to 90 per cent of the increase concentrated in Asia and Africa.
The rapid growth of cities poses sustainability challenges: resource consumption, environmental degradation, energy and water security, among others. But the good news is cities all over the world are increasingly cooperating and sharing strategies to become more sustainable and resilient to shocks and stresses.
Here are our pick of the top 5 cities stories in 2015.
1. Cities take lead in cutting greenhouse gases
In a show of support and to build political momentum for a climate deal at the UN climate summit in Paris earlier this month, cities and regions had gone ahead of national governments to offer record commitments to reduce greenhouse gas emissions and build resilience to climate change.
By mid-November, the UN’s Non-State Actor Zone for Climate Action (NAZCA) database had almost 7,000 pledges which included 2,761 separate actions by 935 cities and 117 regions, making urban centres the largest non-state contributors of climate pledges.
As part of the Lima to Paris Action Agenda (LPAA), cities across the world representing almost a fifth of the global population also launched a five-year vision during the Paris climate talks to scale up actions to tackle climate change. The LPAA is a joint initiative by the Peruvian and French presidencies of the UN meetings - known as COP - which aims to mobilise action towards low-carbon and resilient societies.
This five-year vision, led by the United Nations Framework Convention on Climate Change (UNFCCC), will include:
- Increasing the number of cities and regions deciding to implement an Action Plan and climate objectives;
- Building resilience in the greatest number of cities and regions, with particular attention to vulnerable populations;
- Improving project preparation and climate planning to ensure increased financial flows to the territories, but also accelerate the deployment of innovative economic and financial tools;
- Supporting multi-partnership initiatives between different levels of governance.
2. Low-carbon cities a trillion-dollar opportunity
Low-carbon urban development represents a US$16.6 trillion opportunity by 2050, according to a September report from The Global Commission on the Economy and Climate, an international initiative to analyse the economic risks and opportunities of climate action.
This involves introducing more efficient, cleaner means of transport, and developing and retrofitting sustainable buildings to new green standards. For example, adopting green building standards in Recife, Brazil - with a population of 1.54 million people - could save the city US$90 million by 2030, the report says.
3. Nearly three-quarters of megacities are feeling the effects of climate change
Already, 70 per cent of megacities say they are experiencing the effects of climate change, according to a new report released in early December by the C40 group, a network of cities that are taking action to cut emissions.
For example, more than 26 per cent of cities say they are experiencing heavier rainfall and 17 per cent say they are seeing higher number of hot days. Close to 10 per cent say they are suffering more intense heatwaves. Europe is the most prone to flooding, while North America experiences the most extreme temperature swings.
As more people migrate to cities over the next 30 years, efforts to mitigate climate change will have to be concentrated in urban centres and further stepped up. In Colombia’s capital Bogota,for instance, more landslides have been happening because of more frequent and intense rain. The city authorities have embarked on a tree planting programme to prevent such incidents.
Collectively, the world’s cities have taken more than 9,800 individual climate actions since 2011, half of which are being conducted at the citywide scale, according to C40.
4. Singapore, Seoul, Hong Kong unveiled as Asia’s most sustainable cities
Singapore, South Korea and Hong Kong are among the world’s 10 most environmentally and economically sustainable cities, according to the inaugural Sustainable Cities Index released in February by Dutch design and consultancy firm Arcadis. The cities came in 10th, 7th and 8th, alongside European ones which clinched the other top spots.
The study, conducted by the UK-based think tank Centre for Economics and Business Research, assessed 50 cities on how well they do in the three key areas - people, planet, and profit - widely considered essential to sustainable development.
The Planet index looks at a city’s energy consumption, recycling rates, air pollution, drinking water and sanitation, among others, while a city’s ease of doing business, importance in global economic networks, property and living costs feed into the ‘Profit’ index. The ‘People’ index considers human well-being, quality of life and safety.
5. Beijing pollution worsens, but sees world’s first smog-eating tower
Air pollution is killing about 4,000 people in China a day, accounting for one in six premature deaths in the world’s most populous country, an August study by University of California, Berkeley, showed. These people die from stroke, heart and lung problems.
With the chronic smog in China - and the rest of the world - in mind, Dutch architect Daan Roosegaarde has come up with an innovative solution he says will help cities such as Beijing clean up toxic air and harmful pollutants. Intended to be the ‘largest purifier in the world’, the Smog Free Tower stands at seven metres and uses filters to charge and remove smog particles. It then blows fresh air out of the tower’s side vents, creating ‘bubbles’ of air that are 75 per cent cleaner than that in the rest of the city.
Roosegaarde intends to import this tower to the rest of the world.
This story is part of our Year in Review series, which looks at the top stories that shaped the business and sustainability scene in each of our 11 categories.