Climate Change & Megacities: What can planners do?

Climate crisis has been intensifying in the recent decade as megacities churn out a large amount of GHG emissions everyday. With 5.6 billion people living in urban areas[1], planners are faced with an urgent and important tasks to mitigate climate change by reducing GHG emissions and to make plans to quickly adapt to the inevitable adverse impacts and hazards induced by climate change.

In this essay, I will propose an overall approach and examine strategies that planners can adopt for climate change mitigation (i.e. reducing GHG emissions) and climate change adaption.

(1) A collaborative and coordinated approach for both mitigation and adaptation

A megacity comprises multiple layers and network of agents and stakeholders such as transportation, utilities, industries, developers and communities. Activities of each agent are interconnected and would affect the overall mitigation and adaptation effort. Mitigation and adaptation projects of different scale would also involve multiple agents and stakeholders. Therefore, planners should collaborate with the different agents and produce a coordinated action plan to reduce GHG emissions. For instance, the Hong Kong Climate Action Plan has involved multiple government agencies, utilities, transportation, industries, and even banking[2]. In the UK, it would be wise for the national government to devolve power for local level planning like the GLA for coordinating action plan across councils. Even though this may be beyond the control of planners at local level, local councils can still collaborate with neighbouring councils for a more coordinated climate strategy.

(2) Mitigation strategies

Commitment, targets, monitoring system and communications

Planners should help to develop a city-wide commitment to decarbonisation, set science-based decarbonisation target, establish GHG inventory for regular monitoring and engage in regular communications and collaborative schemes. Cities should communicate their climate commitment to citizens and report on their progress. Planners can enrol their cities to join programmes like CDP[3], which is a rating organisation that provides a standardised platform for cities to report on their GHG emissions annually, develop rating system for cities based on their climate actions and facilitates knowledge sharing among planners and sustainability professionals around the world.

According to GHG protocol[4], a city’s GHG emissions mainly comprises: fuel used for energy generation; fuel and energy used by transportation; energy used by buildings; and energy used for waste and wastewater treatment. The following part will explore possible strategies to tackle each component of GHG emissions for cities.

Renewable energy

To reduce GHG from fuel used for energy generation, planners can source electricity from power companies with low carbon mix or work with power companies towards a low carbon transition by transitioning from fossil fuel to renewable energy sources. For instance, Leeds City Council pledges to purchase all of their electricity from renewable sources[5]. Planner can also enable decentralised renewable energy generation all around the neighbourhood by incentivising homeowners and developers to install PV panels and wind turbines, and utilising unused/vacant land for renewable energy.

Sustainable transport

To reduce GHG from fuel and energy used by transportation, planners can adopt policies to encourage the use of a more sustainable mode of transport. For instance, London established city zones for congestion charge and ULEZ to curb pollutions from older vehicles. These are effective in encouraging people to use public transport. Planners should also plan new settlement by providing good transport links, infrastructure for EVs and active transport network like bike lanes. During COVID, there has been a lot of low cost tactical urbanism initiatives around the world of transforming streets into bike lanes. Planners can adopt such interventions even in the post-COVID world to improve bikability in cities, and thus, to reduce GHG emissions.

Energy efficiency

To reduce GHG from energy use by buildings, planners should focus on pushing forward strategies to improve energy efficiency of buildings. Centre for Cities recommended that planners and local governments can impose higher standards of energy efficiency and carbon emissions through building regulations and trading standards and to improve energy efficiency for low income homes by utilising the Green Homes Grant Local Authority Delivery scheme[6]. For commercial and industrial buildings, planners can work with industry associations and green building councils to educate building owners and operators to adopt energy saving and efficiency technologies.

Circular cities

To reduce GHG from energy used for waste and wastewater treatment, planners can implement circular city strategies to reduce waste and wastewater. Circular city strategies, originate from the concept of circular economy, include: localised energy and food system; closing resources loops through 4Rs; optimised efficiency of resources; sharing of resources; adaptive urban fabric; substitute non-renewable resources; and regenerate natural resources[7]. Interventions like repair cafes and community farms can reduce waste and the derived GHG emissions.

A leading example that combines the above strategies would be Leeds’ Climate Innovation District[8]. Converted from a former brownfield site, it is a well-insulated energy efficient low carbon residential development with rooftop solar panels, car-free street and a well-connected pedestrian, bike and public transport network. Planners elsewhere can also adopt similar strategy by developing ‘low-carbon’ zones.

(3) Adaptation strategies

To protect lives and properties from the destructive impacts from climate change, planners should ensure cities to improve their climate resilience. According to a report by C40, adaptation strategies for cities can be divided into two categories: Systemic resilience actions and Hazards-specific actions[9].

Systemic resilience actions

To properly manage climate risks, planners should adopt risk assessment into different stages of planning. Hazards maps and impact assessments that examine the locations, likelihood and severity of climate risks can be developed to prepare for future emergency responses to hazards. It is also crucial for planners and community NGOs to organise programmes to raise awareness among the public on possible climate risks to enhance public emergency preparedness and adaptive capacity.

Hazards-specific actions

Climate change will bring about chronic and acute hazards and planners can implement the following strategies to tackle them.

Extreme heat: Urban Heat Island (‘UHI’) effect would likely affect densely built urban centres. Planners can deploy design guideline and requirements for building like limit on building height and minimum setbacks to enhance ventilation between buildings. Urban parks, trees on streets, cool roofs and green roofs can also lower the temperature of dense urban centres. An example would be cool roofs initiatives reduce indoor temperature by 5C and improve health of residents in the sweltering slums in India[10].

Flood risks: Planners can adopt sustainable urban drainage systems (SUDS) in cities that are prone to flooding. Features like permeable pavements, swales and rain gardens can increase infiltration and reduce surface runoffs that causes floods. River catchment can be rewilded like the Sussex Flow Initiative to increase infiltration and slow flood flows for River Ouse[11].

Sea level rise: Coastal cities will likely face more frequent storm surges and a long-term increase in sea level, causing the erosion of coastline. Planners in coastal areas need to develop coastal management plans to create buffer zones between the coast and settlements. Nature-based coastal defence like restorations of mangroves by Wetland International in coastal area of Panama City, South Africa and Indonesia[12], and hard defences like rock armour, groynes, breakwater and seawall can protect the coastline and the nearby settlements.

Drought: Planners can deploy water conservation policies and measures with water utility companies. Leakage inspections on water mains should be conducted regularly. Rainwater harvester can be installed in existing homes and new developments to conserve water. Planners can also introduce drought-resistant plants to city parks in drought-prone area.

Health: Climate change can directly and indirectly impact the health of vulnerable groups, such as triggering heat strokes and heart diseases. It is important to build resilience among citizens by promoting healthy lifestyle. Planners can adopt ‘active design’ as proposed by Sport England[13] by improving walkability and providing multifunctional open spaces to engage people in an active lifestyle that is resilient to climate-sensitive health risks.

(4) Conclusion

At the brink of the impending climate disaster, planners worldwide need to act promptly to adapt their cities and neighbourhoods to be resilient to climate risks and hazards. Nevertheless, planners should also remain optimistic and act collaboratively to achieving the Paris pathway of limiting warming within 1.5C by coordinating mitigation measures towards net-zero cities.

References

[1] European Commission, n.d. Competence Centre on Foresight - Urbanisation worldwide. [Online] Available at: https://knowledge4policy.ec.europa.eu/foresight/topic/continuing-urbanisation/urbanisation-worldwide_en [Accessed 10 Jan 2022]. [2] Environment Bureau of Hong Kong, 2021. Hong Kong's Climate Action Plan 2050. [Online] Available at: https://www.climateready.gov.hk/files/pdf/CAP2050_leaflet_en.pdf [Accessed 10 Jan 2022]. [3] CDP, n.d. Cities. [Online] Available at: https://www.cdp.net/en/cities#784e8fc74913ba140954acf5af88b5a8 [Accessed 10 Jan 2022]. [4] Greenhosue Gas Protocol, 2021. Global Protocol for Community-Scale Greenhouse Gas Inventories. [Online] Available at: https://ghgprotocol.org/sites/default/files/standards/GPC_Full_MASTER_RW_v7.pdf [Accessed 10 Jan 2022]. [5] Leeds City Council, n.d. Climate change. [Online] Available at: https://www.leeds.gov.uk/plans-and-strategies/climate-change [Accessed 10 Jan 2022]. [6] Quinio, V. & Rodrigues, G., 2021. Net zero: decarbonising the city. [Online] Available at: https://www.centreforcities.org/wp-content/uploads/2021/07/Net-Zero-Decarbonising-the-City.pdf [Accessed 10 Jan 2022]. [7] Williams, J., 2016. Circular Cities: Strategies, Challenges and Knowledge Gaps, s.l.: Circular Cities Hub. [8] Quinio, V. & Rodrigues, G., 2021. Net zero: decarbonising the city. [Online] Available at: https://www.centreforcities.org/wp-content/uploads/2021/07/Net-Zero-Decarbonising-the-City.pdf [Accessed 10 Jan 2022]. [9] C40, 2021. Focused adaptation. [Online] Available at: https://c40.my.salesforce.com/sfc/p/#36000001Enhz/a/1Q000000A9MA/ZOxO84.z876AUV3tsOFiauSxBcppcUFz0tqEr5xFz7g [Accessed 10 Jan 2022]. [10] Jaiswal, A., 2021. Cool Roofs: Community-Led Initiatives in Four Indian Cities. [Online] Available at: https://www.nrdc.org/experts/anjali-jaiswal/cool-roofs-community-led-initiatives-four-indian-cities [Accessed 10 Jan 2022]. [11] Rewilding Britain, 2016. How rewilding reduces flood risk: A natural approach to flood management that repairs and revitalises our broken ecosystems. [Online] Available at: https://dnu7gk7p9afoo.cloudfront.net/rewildingfloodreportsfi-case-study-2016final.pdf [Accessed 10 Jan 2022]. [12] Wetlands International and The Nature Conservancy, 2014. Mangroves for coastal defence: Guidelines for coastal managers & policy makers. [Online] Available at: https://www.nature.org/media/oceansandcoasts/mangroves-for-coastal-defence.pdf [Accessed Jan 10 2022]. [13] Sport England, 2015. Active Design: Planning for health and wellbeing through sport and physical activity. [Online] Available at: https://sportengland-production-files.s3.eu-west-2.amazonaws.com/s3fs-public/spe003-active-design-published-october-2015-high-quality-for-web-2.pdf?VersionId=uCz_r6UyApzAZlaiEVaNt69DAaOCmklQ [Accessed 10 Jan 2022].