Life Cycle Assessment is used by a wide range of companies, especially when involved in the development of new products or services. Assessing the environmental impact of these helps to provide credibility to customers and stakeholders as well as informing costs and future marketing.
An ISO-compliant LCA provides engineers, designers, and regulators with a blueprint for exploring decisions at each stage of a product or service, including materials, buildings and infrastructure.
As people become increasingly aware of the potential environmental impacts of products or services, an LCA offers a reliable and transparent means for ensuring better decisions are made for the benefit of society as a whole.
An LCA can be broken down into different impact categories, as follows:
- Climate Change: This is a measure of greenhouse gas emissions such as CO2 that are causing climate change. Measuring the carbon footprint associated with a product or service allows these issues to be addressed to prevent negative impacts on the environment, the ecosystem and more.
- Eutrophication: Also known as overfertilisation, this covers the potential impact of excessive levels of macronutrients such as nitrogen or phosphorous in the environment. These macronutrients can lead to changes in species composition both on land and in the aquatic environment. This includes, for example, the proliferation of toxic algal blooms in the oceans, which can depress aquatic oxygen levels as a result of biomass decomposition.
- Acidification: This measures those emissions that increase the concentration of hydrogen ions in water, which decreases the pH value. This can lead to acid rain, for example, which can lead to fish mortality, the decline of forests and the deterioration of building materials.
- Smog: Also known as photochemical ozone creation, this measures emissions that contribute to smog (primarily ozone O3) that is produced by the reaction of carbon monoxide and volatile organic compounds (VOC) in the presence of nitrogen oxides influenced by UV light. Smog, or ground level ozone, can damage crops, harm ecosystems and have a negative impact on human and animal health.
- Particulate Matter: Fossil fuels, wood combustion and dust particles from fields and roads as well as aerosol emissions can cause harmful respiratory effects and increase mortality rates.
- Ozone Depletion: This is a measurement of emissions that deplete the ozone layer in the stratosphere. Depleting the ozone layer allows higher levels of UVB ultraviolet light to penetrate the atmosphere and reach the surface of the Earth, adding to global warming and harming animals, humans and plant-life.
There is a range of terminology associated with Life Cycle Assessments, as follows:
- System Boundary: This splits the activities that are included within the phases of a product or service’s life cycle from those that are not.
- Product System: This covers all of the activities within the system boundary associated with the functional unit.
- Functional Unit: This is a reference against which the functions performed by a product can be assessed. For example, a printer may be assessed against a functional unit of 10,000 pages printed.
- Reference Flow: This relates to the amount of product required to attain the functional unit. This is typically expressed as area, mass, energy used, volume or another physical unit. Where intermediate products or raw materials are being assessed without a specified end use, the reference flow can act as the functional unit.
- Life Cycle Inventory Analysis (LCI): This is the collecting and analysis of the data required to quantify inputs against outputs that cross the system boundary from the product system.
- Life Cycle Impact Assessment (LCIA): This covers the evaluation of any potential environmental impacts based upon the LCI analysis against a set of impact categories.
- Interpretation: By comparing the LCI and LCIA results it is possible to reach a compare scenarios and reach a conclusion so that improvements can be identified.
- Reporting: An LCA study should be clearly reported in accordance with the requirements of ISO 14044.
- Critical Review: Independent experts should confirm conformity to the requirements of ISO 14044. This requires an assessment by three independent experts before a company can assert environmental superiority against another product or service to the public.
A Life Cycle Assessment can be split into four stages, as follows:
- Goal and Scope Definition: The first phase of an LCA is to define the scope of the product or service that you wish to assess. This requires you to decide upon the level of detail required and the basis for any comparison before setting out the objective, application and audience. Once this is done, you can decide if a critical review of your goals are necessary. This allows you to perform the LCA consistently, sets out the definition of your product or service, its life cycle and the system boundaries. The system boundaries set down what is to be assessed and what is not.
- Inventory Analysis: This phase investigates the environmental inputs and outputs associated with your product or service. Inputs can include raw materials that are extracted from the environment or energy use to create a product, while the outputs will include emissions, pollutants or other waste streams. These inputs and outputs combine to create your Life Cycle Inventory (LCI). It is important to collect data correctly to model the LCI as it will feed into the next phase.
- Impact Assessment: This phase translates the data collected and modelled in the LCI and sets them out against impact categories using themes such as environmental impact or human health.
- Interpretation: The final phase involves checking your conclusions using the ISO 14044 standard to make sure they are supported by the data, interpreting the outcomes in relation to any negative effects of your product or service as well as any improvement decisions.
The primary benefit of an LCA is ensuring that your product or service does not have a detrimental effect on the environment, but there are associated business benefits to this too.
Policy-makers and designers can make sure products or services are sustainable, allowing sustainability managers to assess carbon footprint goals for your business. This includes assessing your supply chain to make sure your purchasing department opts for those suppliers who can deliver the most sustainable materials.
With all of this information, marketing teams can define your processes, products and procedures as being environmentally friendly and thereby attract greater customer loyalty, increase sales and improve your revenue too.
An LCA approach can also prevent the problem known as ‘burden shifting,’ whereby an environmental problem solved in one area creates another one further along in the life cycle. For example, removing plastic film from around fruit reduces the impact of this plastic packaging, but can shift the problem further down the line by increasing food waste later. By assessing both of these factors together, an LCA can determine if the use of plastic packaging is more or less harmful than the food waste.
A Life Cycle Assessment is an example of a ‘cradle-to-grave’ process that examines everything from resource extraction and manufacture through to usage, maintenance and disposal. However, there are a number of alternative approaches for determining the impact of a product or service.
These alternatives include those that are considered as partial LCAs:
Cradle-to-Gate:
This is a partial assessment of a product life cycle, stemming from resource extraction (‘cradle’) through to the moment a product leaves the factory (‘gate’). Although the usage and disposal steps found in a full LCA are omitted, a cradle-to-gate assessment can be used as the basis for an Environmental Product Declaration (EPD), which can be useful for assessing the impacts of a production process ahead of resources being purchased by another facility. Steps can be added to determine the impact of transport and further manufacturing down the line to create a fuller LCA.
Cradle-to-Cradle:
Also known as a closed loop production, this takes the disposal step of a cradle-to-grave LCA and creates a recycling stage instead. For example, glass bottles can be recycled to create new glass bottles or other glass products. However, this can sometimes lead to products actually having a shifted or increased burden as a result of the recycling process since it does not assess whether a certified product has a lower overall environmental impact.
Gate-to-Gate:
This process only assesses one value-added process in the production chain, however this can be linked to other steps (such as ‘cradle-to-gate’) to form a fuller picture of a product or service’s impact.
Outside of these partial LCA assessments are those that are aligned to a specific product or service, such as ‘well-to-wheel’ assessments:
Well-to-Wheel (WtW):
A well-to-wheel assessment is specific to measuring the impact of fuels and vehicles. As with a regular LCA, this can also be broken down into smaller segments, such as ‘well-to-station,’ ‘well-to-tank,’ ‘station-to-wheel,’ ‘tank-to-wheel’ and ‘plug-to-wheel.’ WtW is typically used to measure the energy consumption, energy conversion efficiency and emissions of aircraft, marine vessels and motor vehicles. This includes the ‘upstream’ stage of feedstock or fuel production, processing, delivery and energy transmission as well as the ‘downstream’ stage of vehicle operation itself. WtW analysis is used to reflect and compare efficiencies and emissions of different technologies and fuels in both the upstream and downstream stages to provide a more complete picture of the actual environmental impacts of fuels and vehicles. WtW has also informed a model developed by the Argonne National Laboratory known as the ‘Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. This is used to assess the impact of new fuels and vehicle technologies, while a traditional LCA approach is used to determine the impact of the vehicles themselves. The GREET model looks into energy use, greenhouse gas emissions and six other pollutants; carbon monoxide (CO), nitrogen oxide (NOx), particulate matter with size smaller than 10 micrometre (PM10), particulate matter with size smaller than 2.5 micrometre (PM2.5), sulphur oxides (SOx) and volatile organic compounds (VOCs). The emission values found by WtW can differ from those of an LCA, since an LCA will typically consider more emission sources. For example, when considering battery technologies, a WtW will only consider the manufacture and delivery of fuels whereas an LCA will also take account of manufacturing and end-of-life considerations for the batteries too.
There are other modes of Life Cycle Assessment to determine broader impacts at a sector or ecosystem level. These include:
Economic Input–Output Life Cycle Assessment (EIOLCA):
This takes aggregate sector-level data to determine the environmental impact of a sector of the economy and how much each sector purchases from other sectors to create outputs. This allows for long chains to be accounted for, for example building a vehicle requires energy, but this energy requires vehicles for deliver which, in turn, also require energy. Because EIOLCA uses sector-level averages it may not be completely accurate in evaluating the potential environmental impacts of specific products. Plus, an EIOLCA does not validate the translation of economic quantities into environmental impacts. However, EIOLCA is useful in estimating full supply chain implications of a product or service.
Ecologically-Based LCA:
An Ecologically-based LCA, also known as an Eco-LCA, considers a broader range of ecological impacts than a regular LCA. It allows for an understanding of the direct and indirect impacts on ecological resources and the surrounding ecosystems. The Eco-LCA methodology was developed by the Ohio State University Centre for Resilience, categorising services into four groups (cultural, provisioning, regulating, and supporting services) to take account of their impact during the life cycle of products.
Exergy-Based LCA (ExLCA):
Also known as exergetic life cycle assessment or exergoenvironmental analysis, this uses the same framework and objectives as a conventional LCA, but goes deeper into the assessment of resource consumption and the associated environmental impacts. Exergy is the maximum amount of work that can be produced by a system in a given environment. Exergy analysis is a thermodynamic analysis technique based on the Second Law of Thermodynamics that assesses the efficiency of resource use, resource recovery factors, and/or emission rates. It is considered to be more accurate and objective than a conventional LCA and is used to estimate or design different energy systems by evaluating energy conversion or distribution processes. For example, in transport, exergy can account for the total mass to be transported as well as the total distance and the mass per single transport against the delivery time.
The circular economy is a strategy used to minimise resource use and environmental impacts through reducing, recycling and reusing existing resources. The circularity of materials and products can be assessed with a Material Circularity Indicator (MCI) which, when combined with LCA techniques can create a holistic approach for product design.
Life Cycle Assessments (LCA) are used to assess the potential environmental impacts of a product or service across their entire lifespan, from resource acquisition, production, and use to disposal or recycling. LCA provides a comprehensive assessment across a range of potential environmental impacts while avoiding problem shifting from one stage of a life cycle or impact to another.
LCA can increase resource use efficiencies while simultaneously decreasing liabilities. Also known as a ‘cradle-to-grave’ approach, an LCA will identify and quantify the energy and raw materials required as well as associated emissions and waste. These factors are then evaluated against environmental impacts so that options can be explored to reduce the impact of a product or service.