Key aspects of the urban ecological system
A valued ecological system is vital to achieving urban change
Understanding and appreciating ecology and the natural environment is crucial to our urban places.
The ecological system links with the physical and socio-economic systems of an urban environment, and is connected with governance and knowledge sharing to make up the overall urban system.
Cities and towns have always depended on their ecological setting - the natural environment they exist in - to survive and prosper. We have tended to take ecology and nature for granted, as we have built on and over forests, wetlands, rivers, seafronts and deserts.
We need to assess the value of integrating our urban settings with their local ecological environments. For our cities and towns to be thriving, green and resilient places, they must be integrated with nature. By designing and creating our urban environments with an ecological system in mind, we will be better able to deal with the challenges we face - including climate change - and we will have more enjoyable and equitable places in which to live and work, and generally appreciate. We know humankind has the ingenuity to make it happen - we just need to all get on board with the journey to collectively ensure that change happens.
Climate change is here - and we have to act
Aspects of climate change are covered elsewhere on this website. Urban environments are affected by climate change in many ways. Increasing levels of heat threaten lives and livelihoods, flooding does likewise and storms, hurricanes and typhoons wreak havoc.
In January 2021 the United Nations Development Programme (UNDP) released results from a global survey of 1.2 million people about climate change [1]. Almost two-thirds of the people surveyed said that climate change is a global emergency, and that they supported “broad climate policies”, beyond the current situation. Detailed and well-publicised analysis from the IPCC and many other scientific establishments provides us with information on what is happening to the global climate.
Everyone involved with urban environments has a part to play in climate adaptation. Many economic opportunities to change exist, and we can all live better, more purposeful lives when we make changes to our physical and socio-economic urban systems. What are some of the things we need to be aware of, and what can we all do?
[1] UNDP
Climate change and avoiding disasters
Climate change is impacting urban environments all around the world. Heat, flooding, drought and storms all pose major hazards. You can read about examples of hazards in the Urban Disaster Threats section.
We can all play a part to helping our cities and towns to adapt to a changing climate. Are we willing to pay for it, in economically challenging times? Examples and case studies show that when we use the right investment and funding efficiently, we can achieve good outcomes. Everyone needs to be involved in the debate and agreement on actions we need to take.
The vulnerability of the world's urban environments
The need to achieve climate- and disaster-resilient urban environments is as important for small cities and towns as it is for the world’s biggest metropolises. In many cases it is harder for small cities and towns to adapt because they usually have less resources at their disposal. When climate and disaster events occur to small urban and peri-urban areas it can result in people leaving, which results in a smaller local tax base and a vicious cycle can begin of more pressure being placed on funding for their public services. In the worst cases, the very future of a municipality can be at risk.
Tackling the problem with good master planning
The climate is intrinsically part of the ecological system on which we build our towns and cities. The very fact that they are built “over” the ecological system is one of the key principles that has to change. We need to create and use our urban environments “with” nature, not “over” it.
Many urban centres around the world are built on land that is vulnerable to climate change – be it close to the coast, over marshlands and / or in parts of the world where large storms are prevalent. Urban development has to recognise this more clearly. Masterplans need to introduce new policies for better resilience, including nature-based solutions. Many urban environments will benefit from having more greenery, along with the maintenance services (and new economic opportunities) that go with such a change. Decisions on urban development need to be governed according to resilience-based policies, which must be fair and that leave no one behind. Those who are most vulnerable and disadvantaged - the poorest populations of cities and towns - must be protected.
Adopting a mindset of "disasters can be avoided"
With the right action, cities and towns can prevent natural hazards turning into disasters. It is not just a question of spending money – it is about the intelligent use of resources, particularly at the local level. Today, in various parts of the world inefficiencies exist in the allocation of resources towards disaster risk: too much decision-making is made at a high level, and too great a proportion of funding is spent on reactive actions to "repair things after an event occurs”. More effort needs to be focused towards direct, on-the-ground upfront actions and support to avoid disasters.
Can cities and towns achieve Zero Emissions?
The Cities Race to Zero initiative has a goal of enlisting 1,000 cities in support of the COP26 Roadmap of Local Governments and Municipal Authorities (LGMA) Constituency to the United Nations Framework Convention on Climate Change (UNFCCC). It is an initiative organised by the C40 initiative and other partners. It is linked to the Cities Race to Resilience.
The hundreds of cities that have joined the Cities Race to Zero are committed to setting a science-based target for climate change. This is a target in line with delivering a fair share of a 50 per cent global reduction in carbon (CO2) emissions by 2030 and reaching net zero carbon (CO2) emissions by 2050, consistent with limiting global warming to 1.5°C.
What do we mean by Nature-based Solutions?
Nature-based Solutions are either inspired by nature, use nature and/or are supported by nature. They have been defined as “living solutions underpinned by natural processes and structures that are designed to address various environmental challenges while simultaneously providing multiple benefits to economy, society and ecological systems” (European Commission, 2016).
Protecting biodiversity matters to economies. Many ecosystem “services” that are taken for granted, such as crop pollination, water purification and carbon sequestration are vital to allowing our societies to function. In a publication produced in September 2020, Swiss Re Institute’s Biodiversity and Ecosystem Services (BES) Index estimated that 55 per cent of global GDP is dependent on biodiversity and ecosystem services. It highlighted that a fifth of all countries have ecosystems that are in a fragile state for over 30 per cent of their entire area. Yet the value of biodiversity is not specified in public accounts.
Solutions for urban environments that are nature-based can restore the ecological balance in cities and towns, and improve the state of resilience that a city or town has.
Learning from the past
Many ancient cultures had cities that thrived with nature. These ancient civilisations had cities that were spread out across vast areas, integrated into their natural environment.
There were many challenges to sustaining an agricultural system in a dense tropical forest, and the risks associated with nature such as tropical diseases and natural disasters seem obvious. Yet many tropical forest societies of the past developed, and maintained for hundreds of years, successful agricultural methods in challenging circumstances, which sustained large populations and social structures. Recent archaeological exploration, using modern technology including Lidar scanning to map whole areas, has allowed us to discover new insights.
What we have discovered are examples of highly resilient approaches to urban living in the tropics – for shelter, food, transportation and for society in general. Societies including the Classic Maya in Mexico and the Khmer empire of Cambodia were able to prosper for some time, with extensive urban landscapes that were larger than many others (such as Constantinople, and Rome).
Ancient tropical cities were resilient, sometimes surviving many centuries longer than colonial- and industrial-period urban structures. Although they faced immense obstacles, and often had to reinvent themselves to overcome changing climate conditions and their own exploitation of their surrounds, they developed completely new forms of what a city could be.
Cities with rich history where we continue to live and work today also remind us of valuable advice dating back hundreds of years. For example, the gardener and Hoxton (London) resident Thomas Fairchild from the 18th century can still teach us valuable lessons about the challenges of gardening in small urban spaces. His book The City Gardener was published in 1722 (a reprint is nowadays available).
Defining Nature-based Solutions
In addition to international efforts led by the UN and national-level efforts around the world for Nature-based Solutions, academic institutions are providing support in this area.
For example, Oxford University’s Nature-based Solutions Initiative is an interdisciplinary programme of research, education and policy advice whose mission is to enhance understanding of the potential of Nature-based Solutions to address global challenges and support their sustainable implementation worldwide.
Four key points about Nature-based Solutions (NbS) are emphasised by multiple signatories:
1. NbS are not a substitute for the rapid phase-out of fossil fuels and must not delay urgent action to decarbonise our economies (note: this links directly to this Framework’s Governance Section).
2. NbS involve the protection, restoration and/or management of a wide range of natural and semi‐natural ecosystems on land and in the sea; the sustainable management of aquatic systems and working lands; or the creation of novel ecosystems in and around cities or across the wider landscape.
3. NbS are designed, implemented, managed and monitored by or in partnership with Indigenous peoples and local communities through a process that fully respects and champions local rights and knowledge, and generates local benefits.
4. NbS support or enhance biodiversity, that is, the diversity of life from the level of the gene to the level of the ecosystem.
Choosing the right Nature-based Solutions
Project cost-benefit analysis for any initiative should be undertaken. By leveraging the UN SEEA Environmental Accounting framework, for example, it is possible to calculate the value (and hence the cost-benefit) of Nature-based Solutions. Not all proposed solutions will pass the cost-benefit test – assessments must always be objective.
As an example of analysis which looks at cost-benefits of Nature-based Solutions, consider a study published in Nature in 2017 which looked at a major storm and how wetlands protected certain areas that the storm passed over [1]. The study focuses on Hurricane Sandy, which struck the US Northeast in 2012 and caused widespread flooding with at least 72 direct deaths and nearly US$50bn in flood damages, and major disruption to urban centres including New York City. Using an extensive database of property exposure, the regional study showed that wetlands areas avoided US$625m in direct flood damages from the rage of Sandy, such as roads being protected by natural habitat, property being protected and other aspects.
These “big numbers” relate to big events. Nature-based Solutions are not all about the "large scale". Many small initiatives can add up to make a big difference in an urban environment. For some small-scale Nature-based Solutions initiatives, crowdfunding through public support could be an option to make them happen. Nature-based Solutions should also be properly integrated into human-made solutions.
[1] Nature
We can all make Nature-based Solutions happen
Are urban decision-makers – in the public and the private sector (for example, property developers and financiers) – ready, interested and committed to becoming champions of urban biodiversity, urban greening and Nature-based Solutions, and do they have the skills and tools to make it happen? What role can local communities play in the context setting, risk analysis and decision-making process?
To begin with, decision-makers for cities and urban environments need a full understanding and risk assessment of their local natural ecosystems and the biodiversity it contains (which changes over time). Do many cities (and towns also) employ ecologists in their teams, or as contractors / consultants? Biodiversity science is a developing area, and understanding the impact that people and their built environments have on local flora and I in the ecological system is complex. Our awareness and knowledge of biodiversity is improving with sensors and data monitoring environments, and our understanding of the interconnectivity of how everything relates is improving, but there is still a lot more to do.
The current “base” of the ecological system of a city or town is a starting point. Take the relationship with water as one example of many points to be covered. Many cities, old and new, are built on or close to rivers and fluvial systems, or marshland/swamps, or wetlands, or the sea. Urban development in a systems approach requires natural water reserve ecology to be integrated into it. For example, what should be done to retain and leverage the natural characteristics and biodiversity, which for some urban environments requires retrograde changes to reset existing physical systems?
Rather than building on top of and / or draining water systems - which cities around the world have historically done, from London to Lagos, Miami to Mexico City - should planning rules be changed for what can be built, where, and how to take account of water systems (and how developments will change them and the overall environment)? For example, a large housing development on the perimeter of a city or a town may draw water from a local catchment area: what impact would this have on the wider area?
Focusing on nature brings economic benefits
The mindset that biodiversity and cities / towns are interlinked can help us to ensure that Nature-based Solutions are at the heart of urban planning. Urban areas are home to, and are founded on, ecological systems and natural resources which have complex biodiversity to them. Most of us see our trees, see and hear the birds and perhaps hear animals rummaging around garbage bins at night. We do not always make the time to see how nature can and should be integrated into the urban system.
In terms of economic value, we should strive to live and work in cities and towns where the consumption of goods and services leads to more nature, not less, and where employment to pay for these things contributes towards reducing carbon (CO2) emissions, not adding to them. The socio-economic benefits are broad and far-reaching and are discussed in the socio-economic section.
The implementation and ongoing governance of regulations, policies and actions in a city or a town - which should ideally be linked to SDG indicators - can help to ensure cities and towns prevent and protect against biodiversity loss through good land-use policies and healthier and more resilient lifestyle options for citizens. Natural reserves, urban parks, green areas and wetlands contribute to maintaining natural wildlife in urban environments as well as providing many other benefits, from helping the world to tackle climate change to important health and wellbeing benefits for citizens and visitors.
What we can all do to play a part
In both the learning examples given above, local communities have shown how they have valuable knowledge about what happens, and what works “on the ground”. They can play an important role in creating the right solutions that work with nature, for the specific local biodiversity.
Local communities can, for example, pledge their support for policies through voting for initiatives, responding to and commenting on municipal strategic plans, and they can also take part in crowd-funding initiatives. What’s required is the will and imagination for leaders to engage people about it. Perhaps Urban Future / Urban 2.0 centres (discussed in the governance section of this website) can help with this type of engagement.
With regard to the collection of data for science-based decision-making, the prevalence of the smartphone camera means that anyone anywhere in the world can point at a plant or a tree, or perhaps an animal to identify its species and add a record to a designated data set. This is an example of the modern power of citizen cooperation with municipal authorities.
A huge amount of localised data can be used to create information about the biodiversity and ecology of local environments. Apps that support this need can be hugely beneficial socially, by engaging people with their environment and appreciating the nature that exists. In an example of cooperative resilience using public support, in 2016 the Wildlife Conservation Society in New York collaborated with the Woods Hole Oceanographic Institution to use hydrophones in the Hudson river to monitor whale movements. The data were made publicly available and it made the local New York news. When New Yorkers found out about the resident whale population and they could see their movements because of this data, public pressure led to changes being made to shipping lanes and ship speeds so that the whales were given a safer passage.
Greenery is a key area of focus for most cities and towns. Many would benefit hugely from "urban greening", as long as it is done in the right way. Greening of our streets, buildings and other public spaces does more than change the look of these places. Roofs and walls covered in plants, street trees, greenery on the pavements and sidewalks, town and market squares with green spaces and small pocket parks in between buildings make a city / town a better place to live, work and enjoy. A suite of green features act as part of an infrastructure network to help clean the air, combat heat and reduce the risk of flooding.
As one example of urban greening, a city or a town can consider its tree coverage and tree density. The Tree Cities of the World programme is an international effort to recognise cities and towns doing a good job on this aspect. Should all cities and towns sign up to this initiative? In particular, the developing world struggles to ensure there are enough trees – can cities and towns in developed economies help those in developing ones to have more canopy cover (whilst always linking such actions to other parts of the urban system)?
Urban greenery is linked to the socio-economics part of the urban system. For an interesting view about greening our cities and towns, consider reading The Living City by Des Fitzgerald. This book looks at the international green city movement that has expanded around the world and describes the history and roots, which are sometimes troubling, of our aims to connect cities to nature.