In this fascinating article, first published in Liberation School, environmentalist and author Tina Landis explains the concept of sponge cities: what they are, why they are needed, and China’s leading role in developing them.
Tina observes that “the majority of the world’s cities today were built for profit and speculation in mind, with little to no consideration given to negative impacts on either ecology or humanity.”
“Vast hardscapes—sidewalks, roads, parking lots, buildings—and gray infrastructure that channels water away as it falls, places these urban centers at odds with biodiversity and the natural cycling of water through the landscape. Green spaces that are created within urban environments are often highly managed areas separate from the rest of the city, filled with non-native ornamental plants and thirsty grasses that require intensive irrigation, synthetic fertilizers, and pesticides, while providing little to no benefit to native species of birds, insects, and others.”
In an era where humanity faces a rising threat of climate breakdown, developing creative solutions to these problems is literally a matter of life and death. China in particular “is taking comprehensive action to address how urban areas impact the environment and how climate impacts are demanding more resilience in urban planning”, aiming to retrofit and create 30 sponge cities by 2030.
These sponge cities are designed to be climate-resilient population centers. “Sponge cities utilize green infrastructure so that surfaces act as a sponge absorbing water. They integrate space for water to collect such as wetlands and bioswales, create vegetative cover and trees throughout including green roofs and vegetation integrated into building structures, and porous pavement and roads so water can infiltrate soil and catchments underneath to be available during dry times.”
Tina notes that renowned Chinese ecologist and landscape architect Kongjian Yu has been the driving force behind the sponge city movement at a global level. His work has won broad support among China’s political leadership.
Sadly, for the moment, China is the only country developing sponge cities on such a vast scale, as a result of its political system. “Only under a socialist planned economy, like that of China, can real solutions to climate change be implemented on a mass scale.”
Introduction
According to the United Nations Population Fund’s 2009 report, 2008 was the first time in history that over 50 percent of the world’s population resided in cities instead of rural areas. Because of the different ways countries define cities, others date the qualitative shift to as recently as 2021 [1]. Regardless, across the spectrum it’s undisputed we now live in an “urban age” and, as such, transforming the relationship between cities and the natural world is essential for climate change adaptation and mitigation. The international capitalist institutions like the World Bank that are increasingly taking up the issue of cities and climate change can’t explain the various factors behind urbanization nor can they pose real solutions to its impact on or relationship to climate catastrophes. Cities consume 78 percent of the world’s energy resources and produce 60 percent of global greenhouse gas emissions, according to a 2022 UN Habitat report [2]. Under the capitalist model, urban planning lacks a holistic approach, leaving human well being and ecological needs as an afterthought, which will continue to have a degenerative effect on the environment and global climate.
Although Marx and Engels lived during a time in which capitalist urbanization was a nascent phenomenon concentrated mostly in some European cities, like Manchester, the English city about which Friedrich Engels wrote his first and classic book, The Condition of the Working Class in England. Engels demonstrates how the “great town” of Manchester, the first major manufacturing center in England, was great only for capitalist profits. The concentration of capital required for the invention and adoption of machinery outproduced independent handicraft and agricultural production, forcing both into the industrial proletariat of the city. There, they had to work for the capitalists, whose wages were so low they could, if they were lucky, live in overcrowded houses and neighborhoods just outside the city limits. Because the city was produced chaotically for capitalist profits, no attention was given to accompanying environmental impacts [3]. As the masses were driven from their land into the urban factories, the ancestral ties to the land and ecological knowledge of how to live sustainably on that land was lost.
It was not the “industrial revolution” that produced the new sources of power needed for machinery, but the need for new sources of power that produced the industrial revolution. For the machinery required more powerful and reliable sources of energy than wind or the water wheel, animals or humans could provide. They were replaced at first by coal and the steam engine, “whose power was entirely under man’s control, that was mobile and a means of locomotion, that was urban and not, like the water wheel, rural, that permitted production to be concentrated in towns” [4]. Capital was thus not bound to any particular place and free to move and establish new “great towns” wherever they could accumulate the greatest profits, and with this came increasing detrimental effects on people and the planet.
Today’s crisis
We see the result of centuries of unfettered capitalist development in the climate crisis today. Atmospheric rivers, bomb cyclones, hurricanes, heat waves, and drought are all becoming more frequent and extreme with climate change. This summer, with the onset of El Nino, these extremes are amplifying [5].
The first week of July 2023 was the hottest week on Earth ever recorded, with one-third of the United States under excessive-heat advisories. Sweltering heat domes brought triple-digit temperatures across the northern hemisphere from the U.S. to Europe and Asia, while countries in South America experienced record-high temperatures during their winter months [6]. Annually, around 1,500 people die of heat-related deaths in the U.S. States, a count that is likely low since many extreme-heat deaths aren’t documented as such. As of early August, extreme heat in the United States had killed at least 147 people in just five counties in 2023.
As air and water temperatures increase globally, the frequency of extreme weather increases. In the 1980s, billion-dollar disasters occurred every 60 to 120 days on average. In the last decade, they have occurred every 20 to 30 days [7]. Intensifying extreme weather includes more extreme flooding and extreme drought, as the air and water currents globally are becoming destabilized due to the increasing heat in the atmosphere.
Cities were, generally speaking, built near rivers or coastlines. Often, wetlands and floodplains were drained and blockaded with dams and levees to direct water away from population centers. As flooding and drought increase with climate change, these systems are creating even more detrimental conditions in the short and long term.
The U.S. has experienced an urban flooding event every two to three days for the past 25 years, costing $850 billion since 2000. Heavier rains are causing flooding in many parts of the globe, and the eastern U.S. has seen a 70 percent increase in heavy rain events annually [8]. Sea level rise also contributes to flooding events. While the 6.5-inch increase in sea level in the United States may seem minimal, this increase impedes gravity-fed drainage from working during storms and high tides, bringing water into the streets.
Capitalist cities and the surrounding urban sprawl are major contributors to climate change and environmental degradation. The majority of the world’s cities today were built for profit and speculation in mind, with little to no consideration given to negative impacts on either ecology or humanity. They were premised on the idea that nature could be controlled and dominated instead of the proven conception that construction should work collaboratively with natural cycles. Vast hardscapes—sidewalks, roads, parking lots, buildings—and gray infrastructure that channels water away as it falls, places these urban centers at odds with biodiversity and the natural cycling of water through the landscape. Green spaces that are created within urban environments are often highly managed areas separate from the rest of the city, filled with non-native ornamental plants and thirsty grasses that require intensive irrigation, synthetic fertilizers, and pesticides, while providing little to no benefit to native species of birds, insects, and others.
With climate change, the existing city-structures are becoming increasingly disastrous for all residents. The heat island effect that adds more warming to the atmosphere has accelerated deadly implications as the climate warms, making heat waves and droughts even more severe. Hardscapes, such as pavement, buildings, and rooftops, as well as bare earth, absorb solar radiation and continue to radiate heat long after the sun has set. Vehicles, air conditioning units, buildings, and industrial facilities also heat the atmosphere.
The heat island effect results in daytime temperatures in urban areas to be 1-7 degrees Fahrenheit higher than temperatures in outlying areas, and nighttime temperatures about 2 to 5 degrees higher [9].
What can be done? China leads the way
To cool and rebalance the climate, we need to not only eliminate greenhouse gas emissions, but also reduce ecological impacts and restore what has been lost.
Just 40 percent tree cover in a city can reduce temperatures by up to 9 degrees F [10]. Trees and other vegetation not only provide shade from the sun but reduce surrounding air temperatures. Plant leaves are like miniature solar panels and transform solar radiation into sugars and oxygen. Unlike human made structures, plants do not add heat to the surrounding atmosphere; they actually cool the atmosphere when they get hot by releasing water vapor
Water also has a cooling effect on the surroundings due to evaporation. When water bodies are integrated within the landscape they not only cool air temperatures, but also supply hydration to surrounding soil and vegetation, and recharge groundwater. Global heat dynamics regulated by water are between 75-95 percent, so creating more space for water throughout landscapes and urban areas is a key climate change mitigation tool.
Wetlands, floodplains, and bioswales act as flood prevention giving water space to flow and be absorbed into the ground when heavy rains fall, unlike concrete structures that increase the power of water and cause flooding downstream or down the coast from where these structures exist. By allowing water to pool within the landscape, rather than channeling it away into storm drains, rivers and oceans as it falls, makes water available during times of drought. Gray infrastructure flood control mechanisms often fail, with greater frequently in the U.S., which received a “D” on its Infrastructure Report Card from the American Society of Civil Engineers in 2021.
These increasing challenges from climate change are happening globally, but one country in particular is taking comprehensive action to address how urban areas impact the environment and how climate impacts are demanding more resilience in urban planning.
China is one of the countries most severely impacted by floods globally due to geographic and environmental conditions, as well as experiencing increasing droughts and heat waves. To minimize the impacts of climate change, China has implemented their sponge cIty model that aims to retrofit and create 30 cities by 2030 as climate resilient population centers. At a cost of $1 trillion, or around $33.3 billion each, transforming these cities will save billions in annual flood recovery costs and save thousands of lives [11]. For comparison, the U.S. government spends $1 trillion annually just on military expenditures. Imagine what we could accomplish if those funds went to things like sponge cities that improve our lives and the health of the planet!
Sponge cities utilize green infrastructure so that surfaces act as a sponge absorbing water. They integrate space for water to collect such as wetlands and bioswales, create vegetative cover and trees throughout including green roofs and vegetation integrated into building structures, and porous pavement and roads so water can infiltrate soil and catchments underneath to be available during dry times. These cities have areas integrated throughout that have a dual purpose, such as parks adjacent to water bodies that can be enjoyed in dry times, which then act as wetland areas during heavy rains. These sponge cities can deal with four times the amount of rainwater than a normal city, reducing flooding by 50 percent. These cities, when complete, can absorb and reuse 70 percent of rainfall.
How the sponge city movement emerged
China, over the past few decades, has seen major achievements in development. From a mainly agrarian society at the time of the 1949 revolution, China has seen the rapid industrial growth and development of urban centers and has made great achievements in overcoming the legacy underdevelopment imposed by colonial and imperialist powers that the country was plagued with for centuries. At the time of the revolution, extreme poverty, floods and famine plagued the country.
Since that time, China has made major advances, improving the quality of life of the population. In 2020, China eradicated the last vestiges of extreme poverty through the mobilization of Communist Party cadres to the countryside to investigate the needs of the people and bring services and economic opportunities to those most in need [12]. This process which began in 1949 has lifted 850 million out of dire poverty, an unparalleled achievement for humanity.
Chinese culture has historically had a deep connection with nature and connection to ancestral lands. Through rapid development and misunderstanding of the environmental impacts, Chinese cities, as with most cities of the world, have created a separation of the people from nature.
Renowned ecologist and landscape architect, Kongjian Yu, has been the driving force behind the sponge city movement within China and globally, taking inspiration from traditional Chinese irrigation systems [13]. Yu recognized the shortcomings of China’s development path and spearheaded a new way of looking at cities – “big feet” versus “little feet” aesthetics and negative planning [14].
Little feet aesthetics references the debilitating foot binding practices of imperial China that viewed unnaturally small feet on women as beautiful. Yu compares this practice to modern China’s urban development, which often mimics western architecture and imperial Chinese styles with grand plaza and parks that do not serve the general population or ecological needs. These urban parks integrate exotic plants requiring intense irrigation and other inputs with little to no ecological or human benefits.
Yu instead promotes big feet aesthetics, creating green spaces throughout cities using native plants for all populations to interact with in their daily lives that integrate urban areas into the ecosystem rather than inserting a manufactured version of nature for aesthetics only. His argument for big feet aesthetics is to bring people and nature back into coexistence for the well-being of all, which also improves biodiversity and air and water quality, and cools air temperatures. These methods also alleviate flooding and drought, which are increasing with climate change.
Using big-feet aesthetics, Yu has led the eco-city and sponge city movements in China and leads similar projects across the globe. He first made his appeals to local leaders within China and later won over President Xi Jinping to the need to marry development with ecological sustainability. The need to address environmental impacts received broad support within China’s Communist Party which included the goal of building an ecological civilization in their constitution in 2012 [15]. Sponge cities are one of many tools that China is utilizing to achieve that goal [16].
How sponge cities aid in climate change mitigation and adaptation
Yu’s promotion of eco-cities and sponge cities stems from the concept of negative planning, which has its roots in the early Chinese practice of feng-shui and focuses on urban growth based on ecological infrastructure. Rather than a city with green space included here and there, Yu’s eco-city model looks more like a natural area with urban infrastructure woven in.
It is crucial with increasing droughts and floods for urban areas to allow space for water to sit rather than trying to drain it away, which in the end gives water more power and creates flooding in other areas. Slow water systems are being embraced globally as populations experience the negative impacts of gray infrastructure and rains become more intense and erratic.
While water consumption and waste must also be addressed, particularly regarding industrial agriculture and lawns—the single most irrigated crop in the United States—we must also shift away from gray infrastructure to green. Damming of rivers and draining of floodplains and wetlands, not only decimate river ecosystems and harm biodiversity, but inhibit the recharging of groundwater resources. Aquifers are being drained at an alarming rate and as the world warms, water resources are becoming scarcer [17].
Urban development, the creation of hardscapes, and the damming of rivers only continues this trend of a drying landscape, blocking natural water cycling that replenishes groundwater and supports biodiversity.
Yu’s projects aim to work with nature instead of against it, shifting past practices of creating parks as ornamental spaces to ones that mimic wild landscapes filled with native plant species. The use of native plants is crucial to conserve water resources in dry times by greatly reducing or eliminating the need for irrigation and creating a more climate resilient system. Birds, insects and other wildlife benefit from native plant species for food and shelter, increasing overall biodiversity, which in turn increases ecosystem resilience.
A few examples of how detrimental the introduction of non-native plants can be are the example of California and Hawaii. The recent wildfires in Maui were not fueled solely by climate change-induced drought, but also due to the introduction of non-native grasses for livestock feed that dry out quickly and become tinder during drier months [18]. The same is true in California, where early colonizers replaced perennial grasses (which have deep roots and stay green even through the dry season) with annual grasses for livestock feed, which die in early summer, drying out soil and greatly increasing drought and fire risk [19].
The vegetation and bodies of water integrated throughout sponge cities also addresses the heat island effect, lowers air temperatures, and improves air and water quality.
If left to thrive, vegetation captures carbon from the atmosphere aiding in climate change mitigation. Trees absorb carbon dioxide and transpire water vapor and microbes that seed cloud formation and maintain a healthy, balanced small water cycle bringing moderate rainfall rather than deluges. Trees also transpire chemicals that are beneficial to human health, immunity, mental health, and stress reduction. They also act as windbreaks and shelter for animals during storms.
Conclusion
Sponge cities are a crucial tool to address climate change and minimize the negative impacts of urban areas on the overall health of the planet and its inhabitants. Other nature-based solutions such as reforestation of native tree species, a return to agro-ecological methods for food production, and restoration of marine habitats are also key to our survival. None of these solutions will be profitable for corporations to implement, which is why there is a lack of widespread implementation of sponge cities outside of communist China. Only under a socialist planned economy, like that of China, can real solutions to climate change be implemented on a mass scale, as resources are directed to projects not according to the needs of profit, but to those of humanity and the planet.
References
[1] United Nations Population Fund, Annual Report 2008 (New York: UNFP, 2009), 20. Available here; Megha Mukim and Mark Roberts (Eds.), Thriving: Making Cities Green, Resilient, and Inclusive in a Changing Climate (Washington, D.C.: The World Bank, 2023), 75. Available here.
[2] Nicola Tollin, James Vener, Maria Pizzorni, et. al. (2022). Urban Climate Action: The Urban Content of the NCDs: Global Review 2022 (Nairobi: United Nations Human Settlements Programme, 2022), 6. Available here.
[3] Friedrich Engels, The Condition of the Working Class in England (Oxford: Oxford University Press,1845/2009). Available here.
[4] Karl Marx, Capital: A Critique of Political Economy (Vol. 1): A Critical Analysis of Capitalist Production, trans. S. Moore and E. Aveling (New York: International Publishers, 1867/1967), 361.
[5] Tina Landis, “Atmospheric Rivers, Weather Whiplash and the Class Struggle,” Liberation News, 14 January 2023. Available here; Evan Branan and Tina Landis, “Heat Waves Bake the World: Workers Don’t Have to Bear the Brunt,” Liberation News, 13 July 2023. Available here.
[6] Ayesha Tandon, “Record-Breaking 2023 Heat Events Are ‘Not Rare Anymore’ Due to Climate Change,” Carbon Brief, 25 July 2023. Available here.
[7] Climate Matters, “Billion-Dollar Disasters in 2022,” Climate Central, 11 October 2022. Available here.
[8] Flood Defenders, “America’s Most Frequent and Expensive Disaster.” Available here.
[9] Sara Dennis, “Heat Island Effect,” Moody Engineering, 28 September 2022. Available here.
[10] Tamara Iungman, Marta Cirach, Federica Marando, et. al. “Cooling Cities Through Urban Green Infrastructure: A Health Impact Assessment of European Cities,” The Lancet 401, no. 1076 (2023): 577-589.
[11] Tom Carroll, Sponge Cities: A Solarpunk Future by 2030,” Freethink, 28 April 2022. Available here.
[12] Tings Chak, Li Jianhua, and Lilian Zhang, “Serve the People: The Eradication of Extreme Poverty in China,” Tricontinental Institute for Social Research, 23 July 2021. Available here.
[13] See, for example, Xu Tao, Yu Kongjian, Li Dihua, and Miao Wang, “Assessment and Impact Factor Analysis on Stormwater Regulation and Storage Capacity of Urban Green Space in China and Abroad,” China City Planning Review 32, no. 1 (2023): 6-16; Kongian’s website is here.
[14] Kongjian Yu,
Letters to the Leaders of China: Kongjian Yu and the Future of the Chinese City (New York: Terreform, 2018).
[15] The State Council Information Office of the People’s Republic of China, “Document: Responding to Climate Change: China’s Policies and Actions,” China Daily, 28 October 2021. Available here.
[16] Ken Hammond, “China’s Environmental Problems: Beyond the Propaganda,” Liberation School, 08 December 2020. Available here.
[17] Tina Landis, “Colorado River Water Deal: A Bandaid or Real Progress?” Liberation News, 27 May 2023. Available here.
[18] Simon Romero and Serge F. Kovaleski, “How Invasive Plants Caused the Maui Fires to Rage,” The New York Times, 15 August 2023. Available here.
[19] Masanobu Fukuoka, Sowing Seeds in the Desert: Natural Farming, Global Restoration, and Ultimate Food Security (Vermont: Chelsea Green Publishing, 2012).
