The latter point clearly supports cities as being contributors to and victims of climate change. In terms of responsibility for climate change, cities house approximately 50% of the world’s population, are responsible for 75% of global greenhouse gas emissions, and consume two-thirds of global energy supply. Energy consumption falls under the four broad categories of use in housing, food, transport and industry, with housing alone contributing to 32% of global energy consumption, and 19% of global CO2 emissions.
Cities are vulnerable to climate change in a frightening number of ways. Firstly, there are severe health risks posed to cities by climate change due to their high population densities. These include heat stress, with 40000 people (mostly children and the elderly) dying in the 2007 European heatwave, air pollution and the spread of infections diseases such as malaria and dengue fever. With the high concentration of people comes a dense concentration of infrastructure, which is highly vulnerable to extreme weather events, as evidenced with Hurricane Katrina in New Orleans, USA. With the loss of infrastructure and housing, also comes the production of environmental refugees, which are in an even more heightened position of vulnerability compared to regular city dwellers. Lastly, as cities are not self sufficient in terms of food production, the loss of infrastructure also produces extreme food and water scarcity.
Despite these challenges, cities remain our best hopes for tackling climate change. From a scientific perspective, urbanization presents us with a unique set of opportunities to explore solutions to climate change, with the urban population expected to double by 2030 – comprising 60% of the world’s population by that time – and the built-up area tripling by the same time. From a political perspective, policy-makers are increasingly realizing the potential of cities to implement effective solutions to climate change. Cities provide the administrative ease to propose and implement climate change policies, have great potential to combat climate change (given their high contribution to greenhouse gas emissions), and can easily forge collaborative relationships with other cities. For example, in response to the Trump administration’s suggestion to withdraw the US from the Paris Accords, 350 mayors of individual US cities have pledged to provide 100% renewable energy supplies to their communities by 2035. In addition, there are inter-city networks such as ICLEI, 100 Resilient Cities and the Global Convent of Mayors, in addition to the IPCC’s recent panel on cities and climate change in Edmonton, Canada, and their promise to publish a related report by 2020.
The types of solutions that can be developed include mitigation and adaptation measures. Mitigation involves the reduction of greenhouse gas emissions in the short, medium and long terms, and can be categorized under the sectors of waste, transport and housing. Short term mitigation involves lifestyle and behavioural changes as well as retrofitting, such as recycling, thermal comfort in buildings, and intermodal and active travel. In the medium term, mitigation policies involve structural change and urban planning, such as with municipal waste management, zero-waste buildings, and electric vehicle and increased public transport provision. In the long term however, the ultimate goal is to (re)design cities to be compact, connected, coordinated and low carbon, as opposed to the urban sprawl of US cities, which can cost up to $400bn per year. While this long-term goal seems ambitious, it can be achieved through changing our immediate decisions, with newly constructed and planned cities in developing countries – such as in India, where two-thirds of planned buildings in 2030 not being built yet – being based on current consumption patterns. In turn, the appropriate housing and street layout of these future cities can allow short- and medium-turn solutions to be easily implemented when these cities are built.
At the other end of the spectrum lies adaptation, which involves communities making themselves stronger and more resistant to climate change. It is closely entwined with questions of present and future levels of development in developing countries. For example, building infrastructure to accommodate population growth in rapidly growing cities could lead to 225 gigatons of CO2 by 2050. In turn, this raises questions of whether cities in developing countries should be held accountable for their future carbon emissions. Furthermore, while these developing cities would benefit greatly from adaptation measures because of their short-term, localized effects, there needs to be more emphasis placed on encouraging these cities to harness their potential to mitigate a significant portion of future emissions.
In both fields adaptation and mitigation, the importance of experimentation is important. As cities are can be engines of productivity and provide relative ease in implementing climate change policies, they can be viable hotbeds for a wide range of experiments on how to mitigate or adapt to climate change. These include rooftop and façade photovoltaics, zero-carbon or zero-energy housing projects and urban wind turbines. Furthermore, some of these developments are already known to us, such as how smart transport – especially bus rapid transit systems, which can ferry 2 million passengers per day and cost one-fifth that of implementing metro systems – and clean energy can save us up to US$3 billion in the coming years. In conjunction with intercity networks and incorporating a wider range of stakeholders, such as consumers and not-for-profit organizations, the effectiveness of these experiments can be greatly magnified.
However, there are some limits to the potential for cities in influencing climate change. Firstly, certain cities, such as those in India, cannot operate outside of the institutional confines of their nation states, and are required to implement centralized, state-determined policies. Secondly, climate change is just one of the many issues that cities face and tackling climate change may have both synergies and trade-offs with other priorities in the urban context. Lastly, for developing cities the challenge is dedicating themselves to low-carbon, carbon resilient infrastructure despite having relatively low capacity and weak institutions.
These limitations can be overcome. As addressed earlier, developing cities have the potential for climate change mitigation because of the vast degree of future urbanization that lies ahead. One step towards realizing this is through intercity collaboration, and firmly placing climate change as a political priority. Instead of trying to hinder urbanization, which would greatly affect the progress of developing countries, the dichotomy between economic development and a low carbon future should be deconstructed, and an alternative pathway of low-carbon development should be forged. Regarding the deconstruction of preconceived ideas, another crucial concept to clarify would be locked-in carbon emissions, or unavoidable carbon emissions and climate change impacts stemming from current decisions. Cities have the potential to lock-in to low carbon futures, and even to lock-out of current carbon intensive decisions, such as through electrification and retrofitting of existing buildings. While the latter option can be expensive, these new ways locking-in and -out represent new potentials for low carbon futures. In the options pursued, it is important to pay attention to local context. Whether it comes to the feasibility of urban agriculture or ambitious eco-city projects – which would only work on entirely new sites, and a measure to counterbalance the interests of the technocratic elite funding these projects – it is important to consider both environmental and social contexts for implementing these measures. Lastly, in any approach, beyond including a wide range of stakeholders it is important to look at multi-disciplinary, cross sectoral approaches.
The Oxford Climate Society was delighted to host Dr Radhika for the talk and discussion on 7 May 2018 and hopes that it will leave a lasting impression of the potential for what cities can do for climate change.