News & Views

How can Green Infrastructure contribute to Scotlands’ journey to Net-Zero?

The twin crises of climate and biodiversity are no longer new concepts to many of us, especially with the eye of the world on Scotland for COP26 last year. We’re all agreed that they need to be addressed, and with some emergency, but how to do that is still something that we are grappling with.

We have policies that say the right thing and targets to aims for, not least to be net-zero by 2045, so, what do we need to do to achieve that? The answer is not simple, as answers to wicked problems never are, but it lies in a combined effort of mitigation and adaptation activities across all sectors. Whilst we are looking hard into reducing energy use, increasing production by renewable sources, green technologies and adapting our homes and offices to be more efficient, the role of green infrastructure can sometimes be overlooked. It, however, has the potential to make a real contribution to the journey to net-zero, whilst delivering a raft of other environmental, social and economic benefits, not readily quantified. Green Infrastructure is defined in the draft National Planning Framework 4 as:

“Features and spaces in the natural or built environment that provide a range of ecosystem services” .

This definition recognises the multi-functionality of green infrastructure as ecosystem services covers more than just climate action, but also social and economic benefits.

Some of these benefits are:

• Climate mitigation and adaptation
• Flood mitigation, surface and storm water management
• Carbon sequestration
• Energy savings and improved building efficiency
• Water and air quality/ pollution control
• Biodiversity and habitat
• Greenspace improvements
• Amenity and aesthetics
• Traffic management
• Encourages active travel
• Health and well-being, recreation value
• Volunteering, skills and training
• Improved public perception
• Increased property values

Unfortunately, whilst we have good information and data on the contribution that some net-zero strategies and climate mitigation activities make, such as reducing car and air travel and increasing green energy production, green infrastructure benefits vary with many factors, for example weather (not just climate), location, soil conditions, and planting choices. This makes it very difficult to use data from other parts of the world that have been using green infrastructure for some time to try to quantify the contribution it could make in Scotland. For example, green roofs have been used in in Portland, USA for close to 2 decades, and deliver a 12% reduction in energy use along with removing up to 5 toms of carbon emissions each year. However, this is to be closer to 7% energy reduction in northern Europe and perhaps as low as 4% in London. No estimations have been made for Scotland, though green roofs are thought to be more effective at reducing energy use in colder climes. In order to try to rectify this, we need projects here in Scotland, examples of green infrastructure that are properly monitored and evaluated, in order to build that business case for using green infrastructure as standard in the fight to net-zero. We have some great ideas, and projects in development, so the next question is, how do we evaluate these in terms of their benefits?

Tools to measure and evaluate green infrastructure in the UK have been developed, some focussing on very specific interventions or benefits, some trying to capture a wider picture. For example, the Woodland Carbon Code and Peatland Carbon Code have been developed to measure the carbon sequestration benefits of projects that plant trees or restore peatlands, whilst B£ST (Benefits Evaluation Tool) focuses on assessing and monetising many of the financial, social and environmental benefits of blue-green infrastructure. It can be difficult to decide which tool is most suitable for you, therefore, the Ecosystem Knowledge Network has created a Tool Assessor, to help you pick which evaluation tool is most useful for your project.

And yet, this is still only the first step. The data, and the learning, from these projects must be collated somehow, so that an effective picture of the benefits green infrastructure bring can be known and disseminated, so that they can become part of the mainstream battle against climate change.