By 2030, 28% of the world’s population are expected to live in cities of at least one million inhabitants (up from 23% in 2018). Cities are more efficient at using resources, but they also account for 80% of global greenhouse gas emissions. The problems caused by 21st century urbanisation must be resolved if we are to tackle the climate crisis and develop a sustainable economy.
What we need, as Sir James Bevan, Chief Executive of the UK’s Environment Agency, explained at the launch of the ‘State of the Environment’ report last year, are not fewer cities but better ones. It is our cities that drive economies, after all. Urban greening is one of the ways we can make our cities not only more sustainable, but also healthier and happier places to live and work.
In the UK, where 82.9% of people live in urban areas with a population of 10,000 or more,, green infrastructure is considered ‘key infrastructure’.London has taken the initiative. Mayor Sadiq Khan’s London Plan uses an Urban Greening Factor matrix to guide boroughs on the amount of urban greening that should be included in major developments. The Greater London Authority’s aim is to ‘make sure urban greening is included at the start of the development design process’ – an intention that will require landscape professionals to be involved earlier on. Urban greening is no longer an afterthought: the Environment Bill 2021, which comes into force in 2023, will require all planning applications to increase the biodiversity of a site by 10%. At last, nature principles enshrined in law!
Birmingham was the first British city to complete an assessment of its green infrastructure, and increasingly, green urban development is being seen, not as a nice-to-have, but essential to the wellbeing of people and the planet. It is natural capital – what Derbyshire Wildlife Trust calls a ‘Natural Health Service’.
In 2020, the UK’s first micro-forest was planted in Witney, Oxfordshire, and environmental charity Earthwatch plans to plant 150 more in urban areas within the next two years. With space at a premium in many towns and cities, we need to think creatively like this to provide green infrastructure from which all communities can benefit. Botanical features such as living walls and living pillars can provide urban greening solutions in areas of great density. Indeed, the UK’s 10 largest cities welcome green roofs in their local development plans and several – such as Nottingham, Birmingham and Liverpool – say green infrastructure such as living walls should be incorporated into new developments.
Planning policies and environmental agendas of national and local governments are moving us in the right direction. The urban greening of new developments will have a long-term impact, absorbing carbon, removing air pollution, suppressing noise, improving wellbeing, encouraging biodiversity, reducing the urban heat-island and street-canyon effects, lessening flood risk and insulating buildings. A new University of Plymouth study found that living walls can slash a home’s energy bill by reducing the amount of heating lost through its structure by more than 30 percent. However, these solutions can be frustratingly slow in their delivery, which is why we must incorporate green infrastructure into existing structures immediately.
In the short term, we have the innovative products to transform our existing urban infrastructure: turning lighting columns into LivingPillars™ and parkland into micro-forests, and installing living walls onto our buildings.
Architects, developers and urban planners have the opportunity to develop sustainable towns and cities that reconnect us with nature – and remain hospitable in the face of climate change. But we should not sit back and wait for the new developments to incorporate green infrastructure. We should be working to encourage nature back into our built environment now.