Cities as Hotspots for Climate Change
Institute of Policy Studies
1 June 2019

Cities and urban areas are centers of economic and social activities, which makes them hotspots of greenhouse gas (GHG) emissions. Meanwhile, the high concentration of human population and the built environment of cities make them highly vulnerable to impacts of climate change. Repercussions of climate-induced natural disasters on human lives and economic assets are grave. Moreover, urban environments can magnify the impacts of climate change due to their structural features. For instance, during heatwaves, heat is trapped in concrete and asphalt, making cities warmer than the surrounding landscape, a phenomenon widely known as ‘urban heat island effect’. As a result, ill effects of climate change are more profoundly experienced by the urban population.


According to the Urban Development Authority (UDA), Sri Lanka has 264 urban areas. Of them, 24 are relatively larger urban agglomerates, controlled by municipal councils.  In addition, there are also 41 urban councils and several smaller townships coming under Pradeshiya Sabhas.  Among the major cities, Colombo, the country’s economic and administrative capital, alone is home to 1,802,904 people (Department of Census and Statistics, 2012).


Cities are hotspots of green house gas emissions


Transportation and infrastructure in cities are responsible for 75% of the global CO2 emissions (UN Environment, 2019). The former is the main contributor for greenhouse gas emissions in the urban areas of Sri Lanka. Sri Lanka has a high density of roads and more than 25 major cities are connected via the road network (Kumarage and Weerawardana, 2009). More than 500,000 vehicles enter Colombo every day (Eran, 2015). Fossil fuel is utilised as the main energy source for transportation in the country. Heavy traffic can be observed in urban areas, especially during the peak hours. High levels of GHG are emitted to the atmosphere as a result. Additionally, the heavy use of air conditioners in urban areas, especially in Colombo and its suburbs, contribute to GHG emissions during hot days.


Cities are vulnerable to climate change


In 2018, 55.3% of world population lived in urban settlements and 548 cities had over 1 million inhabitants (World Urbanization Prospects, 2018). Those living in cities frequently experience effects of climate change, namely heatwaves, floods, and wind storms. Rising temperature in urban areas result in the urban heat island effect. Even though Sri Lanka lacks data on heat stress, information from other countries are alarming. Over 70,000 deaths occurred due to the heat wave which swept across Europe in 2003 (Robine et al, 2008). Meanwhile, hot days lead to higher energy consumption due to the increased use of air conditioners. Recent power interruptions in Sri Lanka is a good example.

As cities develop, the vegetation is replaced by man-made structures, which limits rain water infiltration and increases surface runoff. Altered precipitation patterns due to climate change will bring more rains in shorter periods of time, making the infiltration process inefficient, while creating excessive surface runoff. This causes flash floods in urban settlements. Sri Lanka has experienced many of these during the recent past. Furthermore, high population in cities will limit access to clean drinking water, as existing sources get polluted.

Moreover, the coastal cities will face rising sea levels and increased frequency of wind storms. According to the Disaster Management Centre, the predicted inundation based on a maximum sea level rise of 0.59m (DMC, 2012) could affect coastal cities and towns. A joint study conducted by UN-Habitat and IPS revealed that 14 coastal cities and towns covered in the study were vulnerable to rising sea levels.

Figure 1: Coastal cities in Sri Lanka

Low-carbon economies and resilient cities


To make cities resilient, effective and timely policy reforms are needed with respect to mitigation, adaptation, and disaster risk reduction. Even though Sri Lanka has introduced certain policies to address these aspects, they have limited focus on urban areas; existing urban development policies do not cover climate change and disaster management adequately. As a result, despite certain efforts taken to address carbon emissions and to increase urban climate resilience, only limited success can be observed.

For instance, the Government has taken certain steps to encourage the use of electric vehicles with zero emissions. But of the lack of charging points available to service these vehicles is a constraint. Efforts to minimise urban traffic is another area that produced little success. Had these plans been made priorities in urban designing and planning stages, it would have been more fruitful. Similarly, climate resilient building designs can help mitigate and adapt to the urban heat island effect. Retrofitting the existing buildings with suitable adaptation measures such as insulations, sunscreens, cooling systems, shutters, and blinds is also important. Mainstreaming such measures into urban planning policies is the way forward to overcoming the challenge of climate change.












  1. S. Kumarage,  J. Weerawardana. (2009). Greater Colombo Traffic Management. 10.13140/RG.2.2.21679.74406.

‌ DCS. (2012). Census of Population and Housing 2012. In (p. 95). Retrieved from Department of Census and Statistics website

Disaster Management Centre. (2012). Hazard Profiles of Sri Lanka. In Retrieved from Disaster Management Centre website:

Eran. (2015, December 14). 500,000 vehicles enter Colombo City daily: Eran. Dailyft. Retrieved from Daily FT

Robine, J. M., Cheung, S. L. K., Le Roy, S., Van Oyen, H., Griffiths, C., Michel, J. P., & Herrmann, F. R. (2008). Death toll exceeded 70,000 in Europe during the summer of 2003. Comptes rendus biologies, 331(2), 171-178.

(2018). 2018 Revision of World Urbanization Prospects | Multimedia Library – United Nations Department of Economic and Social Affairs. Retrieved May 26, 2019, from website:

UN Environment. (2018). Cities and climate change. Retrieved May 29, 2019, from UN Environment website:



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