Calculating the lifecycle environmental impact of complex products: why and how

Calculating the environmental footprint of a large aircraft wing, such as that used in the Airbus A350 or Boeing 787, is a complex job.

For example, many are composite materials of carbon fibres and resins. Making carbon fibres starts with oil or gas, and progresses through chemical steps to produce propane, propylene, polyacrylonitrile and finally carbon fibres. The resin goes through its own series of steps.

Each step may be delivered by a different company. Each company has its own supply chain, energy usage, and a workforce that commutes in each day. Further emissions are created by transportation between them. Each step depends not just on energy used, but the local energy mix. A product produced in Sweden, with its 50% renewably powered grid, will be greener than the same product produced in coal-powered Poland.

And there are other environmental impacts beyond emissions, such as carbon fibre waste at the end of life.

And the wing material is just one part, of one component, of the plane.

With all that complexity, how on earth does a plane manufacturer – or a manufacturer of cars, ships, trains, or any complex product – calculate lifecycle environmental impact?

Why do we need to calculate lifecycle environmental impacts?

First of all, why should we bother with this massive task?

Having granular data on the environmental impact of your product – both in production and in use – is important for reporting, a regulatory requirement in many industries.  It is also, as we will discuss in a separate article, critical for informed decision-making about long-term reduction of environmental impact – about suppliers, materials choices, R&D direction and so on.

How should we perform a lifecycle assessment (LCA)?

There is, on the face, of it a simple answer to this question: follow ISO 14040 & 14044:2006.

This standard defines the methodology and indicators for assessing a product’s lifecycle impacts for analysis purposes. It covers what input data you need to gather upstream (eg raw materials, suppliers, transport) and downstream (in use and end of life).

The concept is sound. But, the difficult bit is getting that data from suppliers and customers.

Some suppliers do a carbon footprint analysis, or even full LCAs, and have a figure for their products. These can be popped into calculators as you move up the supply chain. In an ideal world all suppliers would perform LCAs, and one day this may well be the case. But for now, most suppliers do not. That means we need to do some work to fill in the gaps.

Gathering data on your supply chain

You can push suppliers to share what data they have. Some data may be better than none. But many suppliers don’t have the info, or have not collected it in shareable formats, or will not share it.

If the data points we need are non-existent or not suitable, we need to fall back on databases of industry averages, for example the emissions factor of a specific material, or its recyclability. These are published figures for many materials and processing techniques. But even these are complicated. Different figures exist, for the same material depending, for example, on where it was mined or processed.

The skill, then, is knowing where to look to get the data to meet the methodology.

How should you push your suppliers to send you more data? What can you do with incomplete data (some may be useable with cleansing or combining with benchmark figures)? When should you accept they will not give you data and fall back on databases? Which databases should you use and subscribe to?

These questions all depend heavily on the specific objectives and scenario. The right decision can only come from knowing the methodology, combined with a deep understanding of your industry, the materials it uses, its supply chains, energy requirements, geography and so on. Often this needs to be supplemented with the skills to combine complex (sometimes inconsistent or incomplete) datasets and models, to calculate as best possible the environmental impact.

This is both about accuracy of the input, and about making this complex exercise manageable. Without knowledge and experience, an LCA could produce the wrong answer, or it could take forever, or both.

In the coming years, suppliers will get better at their own analysis and reporting, and these processes can start to become automated, enabling supplier data to automatically update LCA models as things change. That will make the calculations easier, but create new challenges around software design and privacy, as data is shared through the supply chain.

The value of LCA

Bringing this all together gives you a model of models. Multiple models will provide approximations of each part of the supply chain, which will feed into your overall supply chain model.

All this data gives you a picture of your product’s environmental footprint, which you can use for reporting to customers, regulators and shareholders. Right now, this is the goal of most LCAs.

But LCAs serve a far more important purpose. These analysis results can be used to make informed decisions to improve long-term sustainability.

They can identify the environmental impact hotspots where you should focus resources. They highlight how proposed changes will ripple through the supply chain, eg how will changing to a local supplier reduce overall emissions, and if that is worthwhile when set against other environmental impacts. And they help us understand the trade-offs, eg might a material with a higher production footprint still be an environmentally sound decision because it saves fuel over a 20-year lifetime, or can be more easily recycled.

These answers are often not intuitive, and surprise people when they see the results. Reliable data is the only way to know. And making good decisions here is increasingly important to customers and shareholders, and to growth potential within tighter environmental rules.

Lifecycle analyses can be complicated and many companies in your supply chain will not yet have the data collection processes to make your LCA easy. But they need to be done. Doing them well means setting up teams of experts who understand environmental impacts, databases, and the engineering and materials that underpin your industry, and who have the skills to bring this complex data together into reliable systems-level models that provide trustworthy insight.