Cities are a puzzle for some and inspiration for others. As engines of economic growth, they are also hubs of rapid urbanization, a rising middle class, and a growing population. These three mega-trends drive global environmental degradation yet are only part of the important challenge facing cities today.
While consuming over two-thirds of global energy supply and emitting 70% of all carbon dioxide, cities are also uniquely vulnerable to climate change. Fourteen of the world’s 19 largest cities are located in port areas. With sea level rise and increased storm activity, these areas are likely to face coastal flooding, damage to infrastructure, and compromised water and food security. Under these conditions, meeting urban population’s growing production and consumption needs for food, energy, water, and infrastructure will overload rural and urban ecosystems.
To tackle these issues, the Global Environment Facility (GEF), in collaboration with the World Bank Group (WBG), launched the Sustainable Cities Program to engage 23 cities in 11 developing countries. Hailing from one of such countries, two urban development specialists working on each side of the Program explain why making cities more sustainable appeals to them.
For years, the thermal energy beneath the surface of the Earth has been used for many things. Bathing, agriculture, aquaculture, industrial or heating purposes, or even to generate power; the results are often impressive. The Earth’s structure radiates a constant flow of thermal energy outwards to the crust. This phenomenon is a natural, renewable source of heat which provides a substantial contribution to the mitigation of greenhouse gas emissions.
New fracking practices have increased the availability and decreased the cost of natural gas. This is having an enormous impact on energy systems around the world. There are numerous potential applications for natural gas including, but not limited to, use for transportation fuel, residential use, and electricity generation. Since the economic potential of exploiting this resource is so large it is likely that Canada, along with the US, will continue to ‘frack it all’ and reap the economic benefits on the global market. Other countries like China are joining in as well.
The largest increase in use of natural gas is for electricity generation. Natural gas fired power plants are appealing for many reasons. They can supply reliable base-load as well as peaking power. Also, they can be planned and built in less time than say, nuclear power stations, and for lower capital cost. Since fuel is available and cheap, natural gas power plants will continue to be built, and existing plants will continue to operate.
Let’s talk recycling: Not plastic and paper, but power…
These days, by far, the majority of electricity used in high-income countries comes from thermal power plants; these operate by heating water into steam that then spins a turbine. Thermal power plants, however, typically only use 33% to 48% of the total heat they produce. The rest just gets released into water or air. It’s a shame; if only there was a way to recycle all that ‘low-grade’ heat.
Today, 37% of the energy demand in OECD countries is for heating of buildings; only about 21% of energy demand is for electricity. We use much more energy for heating and cooling than we do for electricity. The low-grade heat that gets wasted by most power plants is still hot enough to be used for heating (and cooling) and water heating in buildings.
Why do we use so little of the heat we produce? That’s like buying a tub of fried chicken just to eat the skins!
Reduce, Reuse, Recycle… Recover. As the population in large cities worldwide grows, waste management becomes an even bigger challenge. Recycling programs can divert large amounts of materials from landfills but some garbage still needs to be disposed of in landfills or Energy From Waste (EFW) sites. EFW facilities are capable of recovering energy from garbage that would otherwise be unused in landfills.
EFW and landfill gas capture systems operate on similar principles: produce steam to turn a turbine which generates electricity. The difference is the fuel used to produce the steam. Landfill gas based electricity generation relies on methane from the decomposition of organic material, while EFW facilities combust the solid waste. Both are good options as they prevent methane gas from escaping into the atmosphere. Methane has a global warming potential 72 times that of carbon dioxide. Both options sound good, so which is better? The better question is: ‘How much land and money do you have’?
A helpful way for young math students to grasp the concept of exponential growth is to look at water lilies growing on a pond. They grow exponentially and double in area each day. If they will fully cover the pond by the 30th day, on what day is the lake half covered? The twenty-ninth day.
This year I had the honor of teaching 4th year energy systems students who will graduate later this month (their blogs on energy issues will be presented on this site over the summer). These graduates are particularly essential. During their careers they will be part of the world’s largest ever city-building spree. Their task will be to again double the world’s cities.
The care and feeding of cities is likely the world’s largest business; it’s certainly one of the fastest growing. With an additional 2.5 billion people headed to cities in the next 30 years, providing these ‘customers’ with energy, water, transportation and waste management is critical for local government, as well as a huge opportunity for the private sector. Utilities are big business.
The next five to ten years will see enormous change in the utility sector. How services are combined – does it make sense to have the same utility supply communications infrastructure along with electricity, gas and lights and water supply? How much of a ‘foreign’ company will be allowed to provide local services? What is the best mix of public private partnerships? How will improved efficiencies be measured and rewarded contractually? How can ICT be used more effectively in improved service delivery in the more basic services like water, waste and district heating? How do utilities facilitate services to the urban poor?
Back in 2004, the electrical utility in Brazil’s biggest city had a major problem. AES Eletropaulo was losing a large proportion of its revenue due to almost half-a-million illegal connections, most of them in São Paolo’s slums. Not only that, but they were causing often multiple-house fires on a monthly basis, along with frequent electrocutions. But the utility’s efforts to fix the problem were stymied by its poor relations with slum-dwellers, which made it almost impossible to work in these communities.
The climate, energy and resource challenges facing the planet are daunting. The world’s population continues to grow rapidly, and the majority of people now live in cities. While cities are projected to be home to nearly 70% of our population by 2050, this won’t happen unless society drives significant efficiency gains in all aspects of resource use. Leveraging information will lie at the heart of optimizing resource use.
While projections for city growth are common, we need ask ourselves a simple question -- how much longer will cities be able to service increasing demands for energy, transportation, water, and food without a wholesale transition in the way resources are managed? If we are going to accommodate billions of new urbanites, they will need energy for lights, for heating, for cooling; energy for transportation, housing and emergency services; energy for water systems and sanitation.
In response to the global need for consistency when measuring and reporting greenhouse gas (GHG) emissions, a group of organizations have partnered to develop a Global Protocol for Community-scale Greenhouse Gas Emissions (community protocol). Beginning today and for the next month, the draft edition of the GPC is open for public comment, marking a landmark effort which seeks to harmonize the emissions measurement and reporting process for cities of all sizes and geographies.
“C40 operates under the premise that cities must measure emissions in order to manage them; with this unprecedented and collaborative initiative, we are empowering all cities to do both,” says Jay Carson, CEO of C40.