#WorldEnvironmentDay: Urban Biodiversity - The Need for Green Growth

To celebrate World Environment Day, we hear from Kirsten Johansen of CIBSE's Resilient Cities Group on the need for green growth in our cities:

The loss of biodiversity, together with the changing climate forms an existential planet emergency. Both for the world’s cities and economies. 

At the 2020 World Economic Forum – nature was top of the agenda. The precedence of this was set when the Intergovernmental Panel on Biodiversity and Ecosystems report claimed up to one million species face extinction by 2050. 

Biodiversity needs to be fostered significantly more within the world’s cities. Over half of the population live within cities and it is important to understand the integration of humans and cities - it is our collective responsibility to ensure we include not only pleasant green and blue spaces, but living urban nature to include habitats for wild species.

Urban Design
The benefits of biodiversity within cities is profound. Current urban planning approaches typically consider biodiversity a constraint – a “problem” to be dealt with. At best, biodiversity in urban areas is “offset”, often far from the site of impact.

This is a poor solution because it fails to provide nature in the places where people can benefit most from interacting with it. It also delivers questionable ecological outcomes.

Biodiversity-sensitive urban design (BSUD) aims to create urban environments that make a positive onsite contribution to biodiversity. This involves careful planning and innovative design and architecture. BSUD seeks to build nature into the urban fabric by linking urban planning and design to the basic needs and survival of native plants and animals.

Abrupt Biodiversity Loss and Climate Change
Projections from studies indicate a sharp and sudden loss of biodiversity unless emissions are quickly reduced, up to 50% of species are expected to lose a majority of optimum climate conditions by 2100 and sudden biodiversity loss could occur sooner than expected; ecosystems will be facing a sharp cliff edge as opposed to a climate change slope.

An abrupt loss of biodiversity poses a very significant threat to human well-being. In a vast number of countries, reliance for food security and income is heavily resourced from their immediate natural environment. Abrupt disruption to this will affect their income and food consumption, potentially forcing poverty.

Multi Benefits of Biodiversity
The ecological crisis requires radical change, a re-design of the way we live and in the way our societies are organised. City nature can strengthen local, national, and global diversity.

Greening has a calming and healing effect enhancing human health and well-being. Evidence suggests numerous social and psychological health benefits including stress & anxiety reduction, and overall greater physical and mental wellbeing.

Shinrin-yoku or “forest bathing” is practiced in Japan as preventative healthcare, we are happiest when surrounded by nature which may be due to the evolution of our biophilia co-evolving over the millions of years from human and plant contact.

Plants contribute to cleaner air, reducing harmful pollutants and microscopic matter through complex processes. Unlike parks, urban nature is a living ecosystem. Organisms live and reproduce.

Green areas create cool areas and natural shade, improving city microclimates. Green roofs and walls can provide habitats for wildlife and reduce the impact of the urban heat island, as well as absorbing rainwater and improving building insulation. Greening our cities reverses the steady erosion of the rich earth and allows social connection and happiness in the process.

Due to urbanisation, plant sales have boomed, it is seen as a relief from the over developed cities we live in. People want and desire nature.

Biodiversity and Recent Climates

The last few months have been one of significant interest to climate researchers globally. Within the duration of the COVID-19 pandemic, factories closed, forms of travel became a thing of the past – trains, flights, car traffic all significantly reduced. Entire industries were shut down.

City air pollution around the world dramatically decreased, water quality across large cities vastly increased, overfishing had been depleting fish biomass - this is returning. Sea turtles are returning to areas where they once lay their eggs.

The air is cleaner, the water is clearer, plants are thriving.

As COVID-19 recovery takes economic impact, will open space management take the hit. Easy cuts could potentially have devastating effects on planting diversity and in turn this will affect insects and entire urban ecosystems. There are also inequalities to consider. Access to green space isn’t universal and can further drive inequality within society. Studies have shown links between income inequality, green space access and life expectancy.

Towards a Thriving Future

The greening of our cities is happening in many urban spaces globally. Sadiq Khan aspires to make London a “National Park City” rewilding more than half of the capital by 2050. With a collaborative approach between professional working groups the integration of biodiversity within our cities will help achieve this.

The impact of professions such as engineers, architects, planners and surveyors, to name but a few, on protecting and enhancing biodiversity is enormous. Decisions in relation to roofs, walls, construction materials, the assembly, their disposal and a building’s air and water pollution are all paramount.

The adverse effects of a building on the surrounding environment is in the hands of the professional teams and the protection of biodiversity, for all the reasons above should be pivotal in decision making.

As stated by the United Nations keeping nature and species diversity intact will also protect us against pandemics. We need to appreciate the vital role of the health of our planet and take immediate action to conserve eco-systems.

We have been sent an important message by nature. This positive impact needs to remain globally and across the world’s cities, and together we can contribute towards achieving this.

By Kirsten Johansen


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