In 1996, when the United Nations held its last conference on the urban environment, Habitat II, the city of Nairobi had some 800,000 inhabitants. At that time the ride from the airport to UN Environment headquarters on the other side of the city was something of a mini-safari.
As we prepare for Habitat III, Nairobi has become a bustling metropolitan hub in East Africa, a city of 3.5 million people. The same journey from the airport now takes you past sparkling glass-clad buildings on a six-lane highway, and a number of informal settlements.
Nairobi is just one example of many around the globe that illustrate the dramatic transformation underway in urban areas. A bit more than half of the world’s population lives in cities today. That portion is expected to grow to two-thirds by 2050.
We are living in the age of the city. Decisions we make now on our urban environment have an enormous impact on the future of billions of city dwellers. Can we make the right choices that allow us to live in cities sustainably? Can we harness the transformative power of cities to achieve goals for fighting climate change? Can we use these decisions to make our cities more equitable and secure? Technology is not the limiting factor. It is a matter of choice.
We need to make choices that break down economic and social barriers, while restoring our ecosystems on which we depend for our very survival.
Cities currently account for more than 70 per cent of global energy and resource consumption. But energy efficient technologies and clean energy options are quickly evolving as costs fall. Today, renewable energy capacity far surpasses even the most optimistic forecasts from a couple of decades ago. With this windfall of technology, a number of cities have adopted ambitious objectives. Some, like Copenhagen, aim to be 100 per cent renewable-powered. We need more ambitious targets like this.
How will we transform infrastructure and housing and who will finance it? Much of the technology to make this a positive transformation already exists: walls that store energy for heating or cooling, roofs and windows that collect rainwater and generate electricity. Modern district energy systems can pipe heating and cooling into connected buildings while making use of wasted heat from power stations, industry and local renewables. New York City has district heating systems that provide heat and electricity to critical infrastructure such as hospitals. During Hurricane Sandy, a number of hospitals stayed online because of their district heating system.
One infrastructure technology that has already seen widespread adoption has been bike sharing. Over 500 cities have some form of bike sharing initiative, which is a great complement to public transport. Thinking big, we can imagine that by the time of the next Habitat meeting, autonomous vehicles powered by clean energy may be a core element of city transport systems, reducing local air pollution, and storing renewable energy capacity in vehicle batteries.
Environmentally sound solutions are not necessarily more costly. Often, investments are paid back by lower operating costs. And taking a longer-term perspective, efficiency gains reduce the need for more infrastructure. In Sydney, the city’s comprehensive Energy Efficiency Master Plan estimates that a $166 million investment in residential energy efficiency will result in infrastructure savings of more than $70 million, in addition to direct energy savings of $286 million.
For cities to make the right choices, every economic decision must tell the environmental truth. That means the future cost and risk of environmental impact must be accounted for.
The best choices and solutions will address several challenges at the same time. For example, urban green space in cities caters for recreational activities and makes a city more attractive for its citizens. At the same time, it provides ecosystem services such as cooling down heat islands, cleaning the air and water management. Some studies even point to reduced crime and violence in urban areas with prominent green space.
All of these choices rely on ambition. Does a city want to be healthier, more environmentally friendly, and better-off economically? If it does, there should be no limit to the goals that it sets for itself. What if all cities had the aim of producing zero net waste and zero net carbon emissions? What if all cities aimed to meet World Health Organization air quality standards (only 12 per cent do now)? What if every city aimed for a minimum percentage of public green space? These are questions of aspiration.
Cities have the opportunity to be havens of sustainability, security and equality. What’s required is ambition and commitment.