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Cambridge Institute for Sustainability Leadership (CISL)

27 September 2023 - Dr Tim Forman, Senior Teaching Associate and Course Director of the Interdisciplinary Design for the Built Environment (IDBE) postgraduate courses, explores the relationship between buildings, cities and nature. 

The tendency to act based on personal need and without consideration of adverse impact on others is a behaviour shared across the animal kingdom but manifested most destructively in humans. The ecologist Garret Hardin described this in 1968 as the ‘tragedy of the commons’, drawing on economic theory postulated by William Forster Lloyd nearly 200 years ago but rooted in ancient cultures. In Hardin’s metaphor, the tragedy is that with access to a common (or shared pasture), people will increase numbers of grazing animals for individual benefit, even as the common degrades. Our existence is dependent on the integrity of nature, yet with access to this public good, we act in self-interest not communal benefit – knowingly or unknowingly. 

Natural capital, such as land, water, minerals, plants, trees, and other resources useful to people, and ecosystem services, the regulating forces that maintain ecological balance, are forms of Hardin’s commons. As technology and industrialisation have created unprecedented improvements in the lives of people across the world (despite persistent inequality and poverty for many), social and economic development has led to widening unintended consequences for nature. Conservation and regeneration of natural capital and ecosystem services – as in Hardin’s telling – have fallen victim to individual interest. 

Much of this can be traced to our ‘take-make-waste’ economies, in which real costs of consumption are largely externalised. In Noam Chomsky’s words, ‘markets are lethal, if only because of ignoring externalities, the impacts of their transactions on the environment’. Encouragingly, structural change is afoot, with circular economic activity increasingly common and recognition that there is a vast wealth of untapped opportunities for reuse and regeneration.  

The construction and operation of buildings and infrastructure – our built environment – has outsized impacts on our natural environment. Accurate assessment is challenging, but researchers suggest that the production of concrete alone accounts for 9% of industrial water withdrawals and approximately 1.7% of total water withdrawals globally. Others suggest buildings and construction account for 15% of freshwater withdrawals globally, with national construction sectors accounting for approximately 12 to 15 litres per USD spent (several times higher in one outlier country). An estimated one-sixth to one-half of major resources are consumed by construction and related industries worldwide and tied to the sector. Whether it is depletion of mineral resources, the water crisis, habitat loss, or pollution of land, air or water, impacts on natural capital are often interlinked, and the built environment sector underlies much of the decline in our commons. 

Awareness of our biodiversity emergency (a subset of the broader nature emergency) is increasing, albeit too slowly, as awareness of climate change is increasing, too. These issues are intrinsically related: the integrity of ecosystems and the stability of climate are directly linked. Analysis published by the UN suggests that a 1.5°C increase above pre-industrial temperatures will likely correspond to 4% of mammals losing half of their habitat and 70% to 90% of coral reefs dying, a 2.0°C increase to 8% of animals suffering this plight and 99% of corals reefs dying, and a 3°C increase impacting 41% of mammals. Feedback loops between ecosystems and climate mean that failure to address one emergency leads to compounding worsening of the other. 

So, where do solutions lie? The answer is in ‘top-down’ and ‘bottom-up’ action and leadership.  

Top-down initiatives such as the UN Convention on Biological Diversity (CBD) and the UN Framework Convention on Climate Change (UNFCCC), both established at the 1992 Rio Earth Summit, have provided vital foundations. The Kunming-Montreal Global Biodiversity Framework adopted in 2022 by parties to the CBD and the Paris Agreement adopted under the UNFCCC in 2015 represent significant steps forward – although leave room for much more ambition and action. In the UK, changes this year to the National Planning Policy Framework require 10% net biodiversity gain in and around new developments (on site, off site or through credits). Similar national and local legislation is being developed elsewhere. Finance that underpins built environments is increasingly controlled by regulations and mandated reporting requirements, including the Sustainable Finance Disclosure Regulation, the Task Force on Climate-Related Disclosures and the Task Force on Nature-Related Disclosures. These initiatives are driving the internalisation of externalities. Much more action is needed. 

Bottom-up leadership is observable in myriad contexts. Increasing numbers of buildings and infrastructure projects are completed under rating and certification schemes that compel sustainable procurement, green infrastructure and nature-positive actions. Many architects, engineers, and constructors are delivering projects with smaller resource footprints and more benefits, whether by dematerialising designs using AI, specifying bio-based materials, or improving local habitats. Innovators and suppliers are vital to these changes. Developers are shifting priorities in response to changing public expectation, as clients and users are expecting businesses to reduce consumption, employ regenerative solutions and capture value by adopting circular and nature-sensible strategies. Adopting new social norms, promoting ethical behaviour, technological improvements, and more effective collaboration and information exchange between producers, designers, financiers, constructors, operators, and end-users are sources of hope.  

Our commons cannot afford more tragedy, and the window for restoration and regeneration is closing. More than ever, top-down and bottom-up action and shared leadership are needed to deliver a sustainable transition for the built environment sector. 

Want to make a difference in the built environment sector? Find out more about the Master’s degree or Postgraduate Certificate in Interdisciplinary Design for the Built Environment (IDBE). Applications for 2024 entry for the Master’s degree, Postgraduate Certificate and associated scholarships and bursaries are welcome now. Explore our Building Change hub to find out more about CISL’s work in the built environment sector.  

About the author

Tim Forman

Dr Tim Forman is a Senior Teaching Associate and Course Director of the Interdisciplinary Design for the Built Environment (IDBE) postgraduate courses at the Cambridge Institute for Sustainability Leadership.


The opinions expressed here are those of the authors and do not represent an official position of CISL, the University of Cambridge, or any of its individual business partners or clients.


Zoe Kalus, Head of Media  

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