Green infrastructure, defined: how could it help us solve the climate crisis?
Posted on: 15 April, 2024
Could incorporating green spaces into natural environments help planners balance sustainability and continued development of infrastructure?
As the global population continues to grow, so does the housing crisis. This need to produce quick, affordable housing has resulted in urban sprawl, which is having an even more detrimental impact on our environment.
For one thing, the growth of cities and urban spaces comes at huge expense of the natural world, with most requiring large amounts of natural resources to build.
Plus, these settlements are typically built near valuable ecosystems that provide essential resources like water and materials. This means these built-up areas are slowly depleting and replacing open green spaces.
Unless these natural and urban environments can work together, the future of cities, rural locations and the environment is at stake. However, as we can’t simply put an end to urban living (with over 84% of the UK population currently living in cities), more creative solutions must be found.
Instead, eco-conscious new developments must be created to support the natural world so that both are able to not only survive, but also thrive alongside one another. There needs to be a way for the natural and urban environments to work in harmony and green infrastructure could be the solution to this challenge.
But what is green infrastructure, and how can this play a pivotal role in solving the climate crisis?
What is green infrastructure?
The term green infrastructure refers to strategically planned spaces that are made up of natural and semi-natural areas. These spaces have a number of green features and are designed to solve the current urban and climatic challenges by building with and around nature.
Similar to urban greening, this infrastructure is about incorporating green spaces and assets into urban environments. These spaces can then provide an ecological framework for the social, economic and environmental health of the surrounding areas and the people who live there.
Learn more: What is urban greening (and how is it creating the cities of the future)?
Some of these green assets could include green, open spaces like parks and gardens, woodlands, allotments, ponds, playfields, footpaths and more.
The idea behind green infrastructure is that these spaces are designed and built to provide housing, alongside areas for recreation, habitats for wildlife and environmental services like flood defences and the absorption of air pollution.
For this reason, more governments, as well as the EU, are introducing green infrastructure as part of the environmental initiatives. These bodies aim to promote the use of green infrastructure and nature-based solutions to benefit both citizens and the planet.
In fact, the EU Biodiversity Strategy for 2030 hopes to promote investment in these spaces, to stop the loss of biodiversity and enable ecosystems to deliver their services to people.
Why is it important?
There are several key reasons why green infrastructure is so important right now. For one thing, its role in tackling the climate crisis is crucial, creating green spaces, tackling urban sprawl and helping to reverse damage from the built environment.
Not only this, but cities and urban areas generate 80% of global GDP and house 56% of the world’s people, and this is only set to increase. But cities and their residents are some of the most at risk from the climate crisis and our damaging relationship with the natural world.
The loss of biodiversity and increased risk of natural disasters like floods, pollution and extreme heat, coupled with biodiversity loss in these spaces is putting urban GDP at risk. In fact, in 2019, it was estimated that 44% of urban GDP was under threat and the risk of disruption, particularly in sectors like supply chains, transportation, energy, aviation, IT and more.
Learn more: Building climate resilience into the built environment
With cities not spared by the impact of climate change, these green spaces can be crucial for improving the quality of the environment, connecting more people to nature and boosting the life and health of residents.
So, as well as being better for the planet, green infrastructure supports economic activities and growth, air quality, health and flood regulation.
7 types of green infrastructure
We are used to seeing traditional grey infrastructure like roads, guttering, dams and sea walls used to tackle the flow of rainwater and reduce flooding.
Introducing green infrastructure that incorporates biophilic design instead, can bolster efforts to manage floods and stormwater. It can also boost the local environment, encourage resilience and help to tackle climate change.
Learn more: What is biophilic architecture? 15 real-world examples in the built environment
With more eco-friendly housing estates and villages being built, here are seven types of green infrastructure that are growing in popularity right now:
1. Rain gardens
Rain gardens, as the name suggests, are small, sunken garden areas decorated with plants that collect rainwater runoff from the streets, roofs and pavement. These are designed to mimic the natural way in which water flows and is absorbed into land. This can be particularly helpful for reducing rainwater pollution and flooding.
2. Planters
These are similar to the rain gardens but are small gardens built into planter boxes instead. These also collect and absorb the rain runoff and can be popular alongside pavements, car parks and areas with limited space for a garden. They’re also an attractive feature, as well as being practical.
3. Rainwater harvesting systems
Collecting rainwater for later has a number of benefits. For one thing, it reduces stormwater pollution and slows runoff to help avoid flooding. It can also be used at a later date for watering the plants during drier seasons. These systems might be rain barrels, ground level pits, aquifers and even nets to capture fog and dew.
4. Permeable pavements
Permeable pavements are made from materials like pervious concrete or porous asphalt and are another way to collect rainwater as it falls. The pavement can then treat and store this water. This can reduce flooding and even prevent ice from forming during colder months.
5. Urban forests
Most cities, particularly in the city centres, don’t have too many trees around and they certainly don’t have canopies. But areas of woodland or forest are important for absorbing water and purifying the air. Urban forests are being established to create green spaces in urban locations that once again help to tackle floods and improve the well-being of those living in the area.
6. Green roofs
Green roofs are lightweight and covered in a layer of vegetation that consists of grass, moss, sedum or wildflowers. These can be found on houses, offices and other commercial spaces.
These roofs help to collect rainwater, purify the air and give plants a chance to thrive. These are also a more cost-effective solution in dense urban areas, as lots of the land has already been claimed for building and grey infrastructure.
7. Green parking
There are more cars on the road than ever before and more parking is needed as a result. Green parking can incorporate green infrastructures like permeable pavements, rain gardens and planters, as well as having trees planted around the perimeter.
The benefits of green infrastructure
It’s becoming apparent that green infrastructure is great for both the planet and could be the ideal solution for tackling the climate crisis and reversing the damage of the current built environment. But more than just adding some green space, this new way of building and living can have a positive impact on environmental, social and economic factors. Some of the key benefits include:
Environmental:
- Enhancing urban biodiversity, providing habitats for local wildlife like birds, insects and other species
- Growing native vegetation that is better suited to the rainfall and the local area
- Increasing environmental awareness among urban citizens
- Improving water quality by reducing sediment, unwanted minerals and other contaminants that are usually carried with the runoff
- Managing the flow of rainwater by retaining runoff, slowing the flow and reducing the risk of erosion of the soil bed
- Directing and treating rainwater reduces the need for manual watering and increases soil moisture
Social:
- Encouraging outdoor activities for the locals, including walking, cycling and spending more time amongst nature
- Providing numerous health benefits for those living in these urban areas and improving the health of residents, which is also a factor in disease prevention and epidemics
- Contributing towards the character and identity of a city, softening hard, grey landscapes
- Reducing urban temperatures using trees and green infrastructure for shade and evapotranspiration
- Improving air quality and reducing greenhouse gases for those that live there, as trees remove carbon dioxide, nitrous oxides, sulphur dioxide and more from the atmosphere
Economic:
- Reducing local temperatures and shading building surfaces which cuts down on the need for cooling buildings, which cuts down on energy needs and saves money
- Slowing down the rate of runoff reduces pressure on drainage systems. In fact, it complements grey infrastructure like basins and drainage pipes, lengthening the lifespan of these items
- Enhancing aesthetics and increasing the property values and marketability in greener neighbourhoods
The drawbacks of green infrastructure
Unfortunately, green infrastructure isn’t the remedy for all urban problems and will still have its drawbacks.
For example, these green spaces are more expensive to establish and can be very time-consuming to design and implement. After all, eco-solutions like trees take years to grow.
Plus, they require more frequent and maintenance and monitoring and therefore, they cost more to maintain in the long run. Of course, this will vary depending on the assets, scale and location of the infrastructure.
On top of this, green infrastructure may not always be compatible or welcome within existing urban developments. This could potentially cause conflicts or exacerbate existing social or environmental injustices.
Some designs may have safety concerns like allergies and in lots of cases, these areas require that all residents, contractors, businesses and local authorities be on board before the work can go ahead. This can be tricky depending on the needs, budget and views of those in the area.
Final thoughts
It’s clear that green infrastructure comes with a huge range of benefits to both the planet and those in the local area. From rain gardens to green roofs, there are plenty of assets that can be introduced into both new eco-conscious neighbourhoods and existing developments.
Although these structures may be more expensive in the short term, more needs to be done in order to tackle the climate crisis, growing population and subsequent urban sprawl. Without initiatives like green infrastructure, carbon emissions will continue to rise as a result of the built environment and need for more homes.
As such, those working within the built environment – whether that’s designing, building or maintaining these structures – need to quickly get to grips with green infrastructure and the policies surrounding these new ideas as they continue to evolve and grow in popularity.
Urban planning is an exciting field that has a pivotal role in the design and function of our cities and communities. If you want to have a part in helping the built environment realise a sustainable future, UCEM’s MSc Urban Planning will give you the knowledge, skills and technical understanding you need.
Find out more: MSc Urban Planning – University College of Estate Management
