Box I: The beginning of a public health approach in the mediaeval city of Lucca, Italy ............................................................................................................. xvi Box II: How tuberculosis transformed public space in the United States.................................................................................................................................. xvii Box II: UN-Habitat and CityIQ’s COVID-19 Readiness and Response Tracker ......................................................................................................................... xviii Box 1.1: Correlating air pollution with increased COVID-19 infection rates in the United States

role in creating the predicaments of the present pandemic: “It is very clear that the spread of novel infectious diseases like COVID-19 is an outcome of a growing global population and overexploitation of natural environments”.6 Exposure to such toxic environments has resulted in an increasing number of new vulnerable populations suffering from chronic deficiencies in food, water and energy, making them more susceptible to other medical conditions.7

Air quality has emerged as one predictor of the effects of COVID-19. Respiratory diseases caused by air pollution appear to be a major risk factor and can worsen the course of the disease once contracted. While the exact scientific relation between air pollution and death rates is still being explored, some existing research suggests a correlation. One study of Italian cities found a significant link between chronic exposure to air pollution and the number of severe COVID-19 cases.8 Health experts have warned that poorer households breathe some of the world’s dirtiest air, leaving them disproportionately at risk of dying from the virus.9 A recent study by the European Society of Cardiology estimates that exposure to air pollution increases COVID-19 deaths by 15 per cent worldwide, directly or indirectly, as pollution may also aggravate other health conditions that increase the likelihood of a fatal outcome from the virus. Estimates for the proportion of deaths that could be attributable to air pollution varied considerably between different countries, from as many as 29 per cent of deaths in the Czech Republic, 27 per cent in China and 26 per cent in Germany to as little as 3 per cent in Australia and 1 per cent in New Zealand.10 Such findings about the importance of preventing chronic exposure to poor air quality serve as an important reminder that limiting atmospheric and environmental pollution should be part of a long-term response that builds resilience against pandemics into urban planning. This can be done by addressing local sources of air pollution such as transport emissions, polluting farming practices, waste burning and polluting industries. Promoting improved urban services and a more compact urban form which decreases reliance on motorized forms of transport and air pollution are crucial first steps that will be covered in more detail in section 1.2. Fighting environmental degradation, ecosystem deterioration and deforestation, as well as actively incorporating blue-green infrastructure into urban areas, are crucial components in ensuring urban health and air quality standards.

Respiratory diseases caused by air pollution appear to be a major risk factor and can worsen the course of the disease once contracted

Box 1.1: Correlating air pollution with increased COVID-19 infection rates in the United States

A US nation-wide analysis cross-comparing PM2.5 levels and COVID19-related deaths found that “higher historical PM2.5 exposures are positively associated with higher county-level COVID-19 mortality rates after accounting for many area-level confounders”.11 This correlation shows that a short term adoption of mitigation measures in cities, while welcome, could be of limited effect as continued exposure to emissions can weaken immune systems — underlining the importance of a sustained, long-term strategy to reduce pollution.

Notwithstanding its many challenges, the first lockdown provided the world with a brief window into the decarbonized, sustainable future environmental advocates have championed for decades. Reduced traffic and a halt in other polluting activities such as industrial manufacturing as a result of stay-at-home provisions led to a marked improvement in air quality. Some of the most polluted cities in the world, such as Delhi, enjoyed the lowest levels of air pollution in years — though these benefits proved short-lived.12 Following the dramatic decrease in air pollution during lockdowns

between March and May 2020, a surge in air pollution was observed in many cities globally. In a study by Instant Offices, a workspace provider, using data from the World Air Quality Index, air pollution saw an increase in six out of 15 global cities in the immediate months after emerging from lockdown. In particular, New York City saw the biggest increase with a 33 per cent rise in PM2.5 air pollution in June and July, compared to a 59 per cent drop during the lockdown period in April and May. In other cities, however, air pollution levels continued to fall: for instance, Hong Kong (down 16 per cent during lockdown), Sydney (down 13 per cent) and Singapore (down 14 per cent) saw further reductions of 127 per cent, 35 per cent and 23 per cent respectively following lockdown.13

The sharp reduction in GHG emissions across the world during lockdown was itself an unanticipated side effect of the restrictions that brought much of the global economy to a halt, with far-reaching impacts on the livelihoods and employment of millions of urban residents. Improved air quality, while positive, was therefore the result of necessary emergency measures rather than a concerted strategy to improve the urban environment. Indeed, there is some evidence to suggest that air pollution in many cities has increased even when economic activity has not fully resumed: for instance, a study by the think tank Centre for Cities found that out of a sample of 49 cities in the UK, in 39 (80 per cent) pollution levels had risen to prepandemic levels once lockdown was lifted.14

The lower levels of air pollution evident in cities across the world during lockdown is a reminder of what urban residents should expect as the norm, rather than the exception. The Mayor of London, Sadiq Khan, noting how the city’s air quality had improved significantly in the first weeks of lockdown, went on to add: “But this cleaner air should not just be temporary, as Londoners deserve clean air at all times.”15 These remarks resonate with a common opinion heard throughout political, environmental and multilateral circles during the pandemic. In the words

Figure 1.2: Comparison of PM2.5 levels in major cities before, during and after lockdown restrictions imposed by governments

200

180

160

140

120

100

80

60

40

20

0

Hong Kong Rome Hamburg Singapore London Paris Brisbane Delhi Beijing Los Angeles Melbourne Madrid Sydney Cape Town

Pre-Lockdown (February - March 2020) Peak-Lockdown (April - May 2020) Post-Lockdown (June - July 2020)

New York

of Petteri Taalas, Secretary-General of the World Meteorological Organization: “The world needs to demonstrate the same unity and commitment to climate action and cutting greenhouse gas emissions as to containing the Coronavirus pandemic. Failure in climate change mitigation could lead to greater human life and economic losses during the coming decades.”16 To learn from these experiences and maintain lower pollution levels in the future, a long-term strategy to promote non-motorized modes of transport and compact, mixed-use neighbourhoods should be encouraged, as discussed in sections 1.2 and 1.3 on the city and neighbourhood scales.

The spread of viruses and infections recently has been accelerated by unsustainable urbanization, including “rapid intensification of agriculture, socioeconomic change and ecological fragmentation.”17 More stringent environmental standards, including more holistic resource management, pollution reductions and increased area for the preservation of habitats and biodiversity through the establishment of urban growth boundaries should be prioritized: these measures will reduce both the emergence of new pandemics and help mitigate human-induced climate change. Response and relief funding should also be earmarked for nature-based solutions and ecosystem services that integrate blue, green and grey infrastructure into regional open space and basic service networks, helping regions enhance their climate resilience and advance their socio-economic recovery.18

The linkages between wildlife, domestic animals and the sources, spread and amplifiers of pandemics are critical, but so is “the interconnectedness with issues such as air and water quality, food security and nutrition, and mental and physical health.”19 Pathogens shared with animals – both domestic and wild – make up close to two out of every three diseases infectious to humans.20 This means that animal habitats are a key factor in the emergence of zoonotic diseases, with 50 per cent of all zoonotic diseases estimated to have emerged since 1940, corresponding with a period of enormous forest loss and encroachment.21 Physical changes to the environment can have Animal habitats are a key factor in the emergence of zoonotic diseases, with 50 per cent of all zoonotic diseases estimated to have emerged since 1940, corresponding with a period of enormous forest loss and encroachment