Technology for climate action

Landscape and Carbon Steering Group member Sam Bailey CMLI takes a broad definition of technology to look at how new innovation can help to reduce carbon in landscape projects.

‘Technology: the application of scientific knowledge for practical purposes, especially in industry.’

Taking this broad definition of technology, which could span the digital, mechanical, material or biological and harnessing it to take a perspective from today, one might expect that the rapid advancement of technology this millennium and the explosion of knowledge spawned by the internet, would have spurred a great amount of progress for its use in sustainable development. However, construction can be a slow beast to adapt and the landscape sector remains engrained in traditional construction methods used for many decades. In contrast, buildings and all the elements they are made of, have benefited from technological advancements, including Modern Methods of Construction (MMC) and advances in renewable technology which are making them cleaner and more efficient.

The slow uptake of technological improvements in our industry may be attributed to the inherent perception that landscapes are simply nice, green and environmentally friendly. However, the hidden carbon costs of these projects often go unnoticed. The carbon impact of landscape development is a fraction of building and structural elements, but the carbon reductions that can be made, with relative ease, are significant. Understanding that impact is key and easily comparable knowledge will help bring that into decision-making.

The consideration of carbon in projects presents an important dilemma: How do we balance the creation of biodiverse landscapes, active travel and neighbourhood regeneration while ensuring that the materials and methods we employ to create them do not impose an unsustainable environmental cost? Development is inevitable, so minimising emissions is crucial. Achieving this goal starts with a thorough understanding of the impact our choices have. While awareness of global warming is widespread within the industry, the intricacies of material choices and their carbon costs, along with the data on carbon sequestration through planting, are less understood.

This is no fault of landscape designers and builders – there is simply not enough data for meaningful analysis. The available data is often scattered and inconsistent, making it difficult to make accurate comparisons. However, this should not deter us from making informed decisions based on the information we do have. Current and future technology can aid in both the acquisition of detailed data and better decision-making, but these advancements must work in tandem to facilitate rapid emissions reductions.

Data availability and carbon calculation methods

First, let’s look at the current data landscape. If you are in the world of specifying and using materials in landscapes, some tools are imperative.

Tools like Building Environment Carbon Database (BECD), Embodied Carbon in Construction Calculator (EC3) and the Inventory of Carbon & Energy (ICE) are essentially data hubs where suppliers can submit their Environmental Product Declarations (EPDs). EC3 is also a tool to calculate embodied carbon based on quantities input from models or manually.

EPDs are provided by suppliers to these databases (and others), but often there is little information relating to landscape products. The most common appears to be paving units, but there are few to no EPDs from plant or tree suppliers.

Lifecycle analysis is the process of analysing the long-term environmental impacts of a product or project and this is usually undertaken by specialist sustainability consultants.

OneClickLCA is an example of an external LCA provider which has proprietary tools to calculate environmental impact, but of course this comes at a financial cost to the project.

Analysing the available data is equally as tricky as finding it, but fortunately tools such as Pathfinder by Climate Positive Design (see Landscape Autumn 2023, p49–51 for a review) distil this into more digestible figures, allowing users to create custom materials to upload data that is not found within the system. The Pathfinder tool doesn’t currently link to the above databases but there is a plan to link to EC3 in a new release in the coming months. The Carbon Conscious App by Sasaki8 will also link together with Pathfinder, allowing for a more seamless connection between its own figures for large-scale land carbon analysis and the more detailed specifics attributed to Pathfinder. Both tools are currently the most intuitive on the market, free to use and can help ensure better decision-making. Their current issue is the lack of UK focused data, but by linking into more global databases this will hopefully be improved over time.

Manual calculation is another method of carbon analysis. This can be undertaken using spreadsheets, or schedules linking to Building Information Modelling (BIM). I have previously experimented with this successfully, managing to extract volume and quantity data from Revit models, then creating custom ‘Embodied Carbon’ fields using EPD data, or assumed averages where the data is not known. The schedule then creates totals which can be used to understand the environmental impact of the project better. Vectorworks Landmark has an inbuilt version of this called Vectorworks Embodied Carbon Calculator (VECC).

Unfortunately, there remains little data around the carbon sequestration value of trees and planting. The work required here demands future research and is out of my own area of expertise. Suffice to say it is not definitive, as the growth pattern of trees and planting varies so much on location, climate and soil volume and conditions, but every effort should be made to understand this more.

The Landscape Institute’s Landscape and Carbon Steering Group is currently reviewing the best approaches to calculating landscape project carbon, including embodied carbon and sequestered carbon and will be providing guidance for the industry on this in due course.

Strategies for immediate emissions reductions

Making informed choices to reduce emissions involves a broad understanding of existing materials and alternative construction methods, along with a good knowledge of the material impact.

Alongside the analysis of proposed designs, using BIM models or manual drawing take-offs to calculate existing on-site materials can inform the potential reuse of materials. For example, the reuse of existing bricks within gabion baskets, or existing paving materials repurposed into new patterns and areas, can provide huge carbon savings instead of extracting, producing and transporting materials to site. Similarly, measures of existing concrete can be taken and analysed with a view to crushing and reusing the material in subbases or similar. This way of working has been highlighted in the work of architect Duncan Baker Brown and explored in practice in the influential Pheonix project by Periscope and Human Nature.

Use of drone surveys for complex 3D scans, or even the Polycam app, can enable you to survey existing furniture, fencing, boulders, walls and topography to analyse what is on site. Incorporating these into your own model and designs has the potential to make immediate carbon savings. Practical risk concerns are understandable as we don’t want to see catastrophic material failure, but the risks associated with reusing materials in landscape projects are much lower than other industries and will hopefully enable the industry to create a culture change, bringing clients and contractors on board.

Gone are the days when every site element should be ‘off the shelf’; designers should now be looking to adapt and reuse.

This principle is key to improving the circular economy and platforms such as Building Material Exchange provide a central digital location for trading excess, recycled or repurposed building materials. European counterparts are also exploring this, as illustrated by Superuse, which created an innovative playground from disused wind turbine propellers.

Soil reuse is a huge one to understand, as any disturbance of existing soil will have knock-on carbon implications and the carbon emissions for the import and transportation of new soil can be significant, potentially outweighing the carbon benefits of planting a few trees in the area.

The Landscape Institute’s Landscape and Carbon Steering Group is currently reviewing the best approaches to calculating landscape project carbon

Experimental techniques in growing mediums have long been explored by the University of Sheffield, for example using aggregates, recycled bricks and other waste materials for creating drought-tolerant, free-draining planting areas, as evidenced by the Grey to Green scheme in Sheffield. It comes back to the reuse: what is on site that can be successfully mined and incorporated, in turn bringing carbon savings by not extracting, processing and developing more materials.

When specifying new products and materials, consideration should be given to the impact those materials have. A useful resource for a broad understanding is the Material Triangle, which makes it easy to quickly compare the carbon footprints of different materials. At the top are key culprits aluminium, galvanised steel and glass. It’s easy to say that we should avoid using these materials, but the question of what can replace them should also be raised. If we replace aluminium with steel, to what extent will it decrease the longevity of the product? If we specify weathered steel instead of galvanised, how long will it last? Is it better to specify galvanised if it were to last twice as long? Is it better to install timber fencing with the knowledge that it may only last 20 years before replacement, or would it be better to accept the carbon cost of something more robust that lasts longer? Time is an important consideration when dealing with carbon and will often be a nuanced one, depending on the situation and maintenance requirements. I don’t know the answer to these questions, but they show the importance of standardised EPDs, provided by suppliers across sectors, to allow us to make informed decisions.

AI could help us analyse EPDs and complex data much quicker, allowing us to draw conclusions which influence project decisions; however, this technology is still in its infancy and can often misinterpret data it hasn’t been fully trained on. Advancements will improve this and AI is likely to be a key factor in improving our understanding, if only through its processing speed in the near future.

Embracing technology in landscape architecture offers immense potential for reducing carbon emissions and creating more sustainable environments. By understanding and improving on the these technologies (digital and non-digital) and adopting pioneering practices already being explored experimentally, there are huge carbon savings that can be achieved with relative ease, creating a positive lasting impact for the climate.

Sam Bailey CMLI is an independent chartered landscape architect working with a range of practices across the UK and a member of The Landscape Institute Landscape and Carbon Steering Group.