Assessing the importance of Life Cycle Assessment

New Nature article reviews the sustainability measurement tool in providing solutions for the triple planetary crises.

How sustainable are the self-proclaimed sustainable products one finds in today's supermarkets? If you are an eco-conscious citizen, chances are that you tend to look for various statements that claim the products being manufactured in a certain way – use of natural ingredients maybe, or of recycling. But does that guarantee that the recycled toothbrush you have been using or the à-la-mode backpack made from plastic bottles actually have lower impact on the environment? There is a way to find that out. Life Cycle assessment or LCA is one of the most widely used methodologies used to measure sustainability of a product (or a system).

“LCA was initiated in industry in the 1960s and has since then been substantially developed in academia and standardized by ISO,” says Enrico Benetto, Head of the Environmental Sustainability Assessment and Circularity Unit at LIST. Benetto has recently co-authored an article on LCA for Nature, which discusses the role of LCA in addressing the three major issues the world is facing today: climate change, biodiversity and pollution.

LCA – a “cradle-to-grave” and “cradle-to-cradle” analysis

LCA aims to evaluate the environmental impacts of products comprehensively. Unlike conventional assessments that might only consider, for example, the use phase of a product, LCA examines the entire product life cycle, from creation to disposal, encompassing the entire value and supply chain, including circularity. This holistic approach provides a global perspective, preventing the optimization of a product for one phase at the expense of others. For instance, optimizing a component for reduced pollution during product use may inadvertently increase pollution during its production.

“Take the example of electric cars,” says Benetto. “Although it is scientifically proven that overall, they are substantially better than conventional internal combustion engine vehicles in mitigating climate change from individual mobility, they are not impact-free. During their use phase, electric cars have zero carbon emissions, but the production of electricity used may be carbon intensive.”

Moreover, LCA doesn't focus solely on one environmental impact. Instead, it considers multiple impacts on protection areas such as human health, ecosystems, biodiversity, and resource consumption. “It is essential to recognize that efforts to mitigate one impact should not exacerbate others. Critical raw materials are used in the production of batteries for electric vehicles, for example. A holistic assessment using LCA is therefore needed to understand the trade-offs, and under which conditions the overall environmental impacts are reduced the most,” he adds.

Assessing sustainability – from products to systems

LCA is typically used to compare products or processes, but it is now being used to address bigger challenges like reducing carbon emissions, creating a circular economy, promoting sustainable consumption, and making finance more sustainable. When it comes to individual products or processes, LCA has clear guidelines and standards to follow, but for larger, economy-wide studies, the methods are still evolving and not standardized.

A crucial message in the article is this shift towards assessing large-scale systems rather than single products. This involves examining entire value chains and considering how changes at one level affect stability at other levels. For example, according to the researchers, policies addressing sustainable consumption should be studied not just at the individual consumer level but also at the national or territorial level to account for potential ripple effects in the population and production systems. Or, LCA studies that are focused solely on climate change, should consider multiple environmental indicators, including biodiversity loss.

“Researchers are combining LCA with other tools like Integrated Assessment Models (IAMs) and Material Flow Analysis (MFA) to get a more comprehensive view of environmental impacts,” Benetto explains. “These combinations are being used to explore scenarios for achieving climate goals, improving consumption patterns, and understanding the circular economy's impact.”

While these combinations of tools have shown promise, the study emphasizes that there is still work to be done to make them more standardized and helpful for policymakers. “By standardizing these methods, we can better address the complex challenges related to the triple planetary crisis of climate change, resource depletion, and environmental degradation,” he adds. “Ultimately, LCA can play a crucial role in guiding us toward a sustainable future, but we need to put this knowledge into action to make a real difference.”

The article has been authored by Stefanie Hellweg (ETH Zurich), Enrico Benetto (LIST), Mark A. J. Huijbregts (Radboud University, Nijmegen), Francesca Verones and Richard Wood (Norwegian University of Science and Technology).