Climate disruption is exacerbating urban challenges such as heat islands, air pollution and extreme weather events, to mention a few. The effects of a changing climate will impact all aspects of urban society, including infrastructure systems, public services, the built environment, and ecosystem services (IIED). While these challenges disproportionately affect economically disadvantaged and minority communities, they also bring serious political, social, and economic repercussions for entire cities.
Cities are growing at an unpresented rate today, particularly in the developing world, where 1.4 million people are added to urban areas each week (The New Climate Economy, 2015). By 2030, around 60 percent of the global population will live in cities and a vast majority of them in coastal regions. For cities, it is vital that they can operate and function resiliently, even as climate change subjects them to an increasing number of extreme and disruptive weather events. Resilient cities are important for everyday life as well as for the global economy, as more than 80 percent of the global GDP is produced in urban areas (World Bank, 2016).
Climate change will impose a range of different potential risks to cities (Rosenzweig et al. 2015). One risk is the increasing prevalence of urban heat islands – a phenomenon in which urban centres and cities are several degrees warmer than surrounding areas due to presence of heat absorbing material, reduced evaporative cooling caused by lack of vegetation, and production of waste heat. The warming climate combined with urban heat islands increases the need for cooling and air conditioning systems, which in turn increase energy consumption in cities. In addition to heat islands, other climate related risks to cities include for example heavy downpours and flooding with cascading impacts on critical systems such as energy supply, food distribution and logistics in general.
Cities do not just experience the effects of climate change, they also contribute to their creation, as today, cities generate 70-75 percent of energy related greenhouse gasses. Spurred by the need to act, and invigorated by the COP21 climate agreement, a number of cities have developed climate action – and adaptation plans. However, for many local governments, this task can be seen as overwhelming when faced with such complex and interdisciplinary challenges involving disparate stakeholders and planning agencies.
Finally, climate disruption does not hit people equally. Economically disadvantaged and minority communities tend to live in more hazard-prone, vulnerable and crowded parts of cities (Rosenzweig et al. 2015). These circumstances increase their susceptibility to the impacts of climate disruption and reduce their capacity to adapt to and withstand extreme events. As of now, one billion urban dwellers live in informal settlements which lack provision for risk-reducing infrastructure and basic services. Their homes and livelihoods are also often those most at risk from the impacts of climate disruption (Bartlett & Satterthwaite, 2016).
Climate disruption is already costly for cities globally. Climate change-induced urban flooding alone is estimated to cost approximately USD 1 trillion a year, globally, and the annual cost of adaptation measuresis estimated to range between USD 80-100 billion, of which about 80 percent will be borne in urbanized areas (Rosenzweig et al. 2015). These figures will only rise as
cities are increasingly disrupted by climate change and must work faster and quicker to mitigate and adapt to its effects.