Let’s act with Life cycle assessment (LCA) in mind

Carbon neutral

Circular economy


In order to achieve a carbon neutral society by 2050, business activities, consumer behavior, and society need to change. Against this backdrop, Life Cycle Assessment (LCA), which calculates and visualizes the environmental impact of a product lifecycle from its raw material extraction to final disposal, is attracting attention as a mechanism to promote products and services with low environmental impact in society. We asked Masahiko Hirao, a leading expert on LCA, about the current status, problems, and future prospects of LCA.

平尾 雅彦HIRAO Masahiko

Senior Research Fellow
Research Center for Advanced Science and Technology, The University of Tokyo

He is working with companies on Pre-emptive LCA research in UTLCA’s Pre-emptive LCA Social Cooperation Research Department.

What is LCA?

LCA is a method for evaluating the environmental impact of the lifecycle of products and services. The lifecycle of a human being is from birth to death, and this is what we are looking at for products and services as well. This method quantitatively evaluates how much energy and resources are used, how much greenhouse gas, water and other substances are emitted through the lifecycle, and the resulting impact on the global environment.

Figure 1: Life Cycle of Chemical Products

For example, you may know that plastics, which are made from petroleum, used in most products around you, but you may not know what happens in the lifecycle (Figure 1). First, the refinery industry distills imported crude oil to extract a substance called naphtha, which is then cracked by the petrochemical industry to produce ethylene, propylene, and other chemicals that are the basis of plastics. These molecules are then polymerized to produce polyethylene, used in plastic shopping bags, and polypropylene, used to make the white cap of PET bottles. Plastics have plasticity and change shape when heated, so they can be melted, inflated and molded into a variety of products.

Energy is used in each step of the manufacturing process, and fuel is also used for transportation in between. Even after the product is disposed of, CO₂ is produced if it is incinerated as waste, and, even if it is recycled, energy is used in the transportation and recycling processes. LCA considers not only the environmental impact of a product when it is used, but also how it is made, what happens after it is discarded, that is to say, the environmental impact from resource extraction from the earth to returning waste to the earth. In addition to global warming caused by greenhouse gas emissions, we also evaluate ozone layer depletion caused by CFC gases, and water consumption, organic matter discharged into rivers and see water (Figure 2).

Figure 2: Assessment of environmental impact by LCA

When and where did the LCA concept propose?

It is said that the first case was in 1969, when the Coca-Cola Company of the United States conducted a comparative environmental impact assessment to determine whether glass bottle or plastic bottle are better for the environment as container for Coca-Cola. Since then, research on evaluation methods has progressed, and in the 1990s, researchers created a standard procedure for LCA, which became a standard by the International Organization for Standardization (ISO). In the 21st century, many LCA practices have been conducted in accordance with the ISO standard (Figure 3).

Figure 3: LCA evaluation procedure according to ISO standards

LCA is conducted based on the framework defined in the ISO standard as shown in this figure: 1) Define the goal and scope, considering impacts to be evaluated, and the purpose and scope of the study; 2) Collect material and energy input and output data for each stage of the life cycle, and prepare an inventory table for the lifecycle; 3) Quantitatively evaluate the impact on each environmental category based on the inventory analysis in 2). 4) Identify important items and draw conclusions.

The reality of LCA practice

Is LCA used in Japanese manufacturing?

In many industrial sectors, there has been momentum to implement LCA since the 1990s, and in 1995 the “Society of LCA Japan” was established as a platform for industry, government, and academia to come together. In fact, Japanese companies are among the most advanced in the world in terms of “environmentally conscious product manufacturing”.

In particular, major automobile and electronics manufacturers that are expanding overseas are highly sensitive to LCA, and use LCA to calculate the differences in environmental impact of different materials, mainly at the product design stage. For example, the environmental impact of which type of electric vehicle and over what distance is calculated by LCA, and this information is publicly available. However, consumers do not use such information to make decisions when choosing a car. Companies may not see the benefit of publishing LCA results because they know that there is not a high level of interest.

Japan’s collection rate for PET bottles is outstanding in the world, but how did LCA work here?

I think LCA has made a contribution. From early on, the Council for PET Bottle Recycling performed LCA and reported how much GHG emissions were reduced by recycling. There were arguments against recycling because it could increase the environmental impacts, but the results of the LCA showed that recycling lowers environmental impacts, and this has encouraged people to recycle.

Japan was an early adopter of recycling and efficient use of resources, and in 2001, the country became the first in the world to enact the Basic Act for Establishing a Sound Material-Cycle Society, which clearly states the concept that producers assumes a certain level of responsibility not only at the manufacturing stage, but also for recycling and disposal of products after use. Individual recycling laws based on this law are probably the best system in the world.

In this context, the development of plastic recycling technologies is also being actively pursued. For example, about half of the plastic containers and packaging collected after sorting is used to reduce iron ore in blast furnaces as a substitute for coke. It is not simply a matter of feeding the material into a blast furnace; it requires a high level of technology, but this has been accomplished. LCA has confirmed that this method can reduce environmental impact.

Chemical recycling, in which waste plastic is chemically decomposed and gasified to be used as a chemical raw material, has also been an early example. Our “bottle-to-bottle” recycling technology, in which used plastic bottles are recycled into new bottles, is the most advanced in the world.

However, these Japanese recycling schemes and efforts are little known overseas. This is because there are few materials published in English by either government agencies or companies. It is unfortunate that the Japanese media do not have a proper understanding of the actual situation in Japan, and the dominant argument is that Japan lags behind Europe.

What are the challenges of implementing LCA?

It is not always possible to verify that the data used in the calculation is correct. One such case is when detailed values are not available. For example, if a product is recycled in a certain way, it is difficult to accurately calculate how much energy was used, such as the distance it was transported, the fuel efficiency of the vehicles used to do so, and the electricity used in the factory. In such cases, we use values that are considered average.

Another is that it is difficult to collect data. Even if detailed values are available, they may not be disclosed because they relate to the competitiveness of the company. For the materials industry, the cost of basic raw materials and energy is data that directly affects competitiveness, so it is difficult to disclose. Therefore, if we can estimate them from academic literature, we use those values.

General-purpose plastics such as polyethylene are made by several companies, so the data may be published in the form of an overall average. However, fuels, production methods, and the scale of facilities should really differ from plant to plant, so we cannot know the real data for each plant. Therefore, we sometimes use simulation data. A chemical factory is virtually built on a computer to reproduce the process and calculate the amount of energy, emissions, etc. required.

Now, through the efforts of the National Institute of Advanced Industrial Science and Technology (AIST), a database with the data necessary to conduct such LCA is also available.

Companies under pressure to respond

How will companies’ stance on environmental information disclosure and the direction of technological development change in order to achieve carbon neutrality in 2050?

From now on, companies cannot afford not to disclose environmental information. The Ministry of Economy, Trade and Industry (METI) and the Ministry of the Environment (MOE) compiled the “Carbon Footprint Guidelines” in March 2023 and published a practical guide in May. These are guidelines for companies to calculate and disclose their carbon footprint (the total amount of greenhouse gases (GHG) emitted during the lifecycle of a product converted to CO₂ emission). The government also believes that if such information is not disclosed, the economy will not be able to stand on an international level.

Apple Inc. in the U.S. has already requested that its suppliers of materials and parts manufacture their products using clean power from solar, wind, and other sources. As a result, suppliers are using renewable energy only for their production lines for Apple. As this trend spreads, upstream materials industries that currently rely on fossil resources for energy and raw materials will be forced to use materials derived from renewable energy and non-fossil resources.

Steelmakers are therefore researching ways to produce iron using hydrogen instead of coke. Chemical manufacturers are also researching biomass-derived plastics and making plastics from CO₂ in the air. Many companies are creating management scenarios that will put new technologies to practical use by 2030, back casting from 2050. Times are tough for companies, but if they do not do so, they will not be able to survive. I believe that even industries that did not previously disclose LCA results or data necessary for LCA will move toward doing so.

Recently, the European Union (EU) has set numerical targets for automotive, industrial, portable, and other batteries sold in the region, including collection rates for discarded batteries and recycling rates by raw material, and manufacturers are required to gradually achieve these targets starting in 2024. Regulations on the environmental impact of products tend to be set first in Europe. How do you think this will affect Japanese manufacturers?

The EU has a research institute called Joint Research Center for policy making, and there are many LCA experts there. Policies are made top-down, and because of the diplomatic power of the EU, there is a tendency for each country to conform to the standards set by Europe.

There is an aspect that the adoption of LCA is progressing because Europe is leading the way, and this should be appreciated, but there are likely to be some aspects that will be difficult for Japanese manufacturers. In fact, we have heard that when a Japanese manufacturer presented a new material to a European company, it was told to conduct LCA based on European standards and provide results. However, Japan has also been an early participant in discussions on the creation of standards in ISO, so it may be able to play a certain role in the creation of international standards.

With companies rushing to go carbon neutral, what is the aim of the University of Tokyo in establishing the UTokyo LCA Center for Future Strategy (UTLCA)?

For current products and services, companies can calculate LCA by themselves since there is a database and software for LCA. However, technologies currently under development will be implemented as various changes occur toward achieving carbon neutral society. However, the current LCA database cannot be used to calculate the LCA at that time; the LCA database contains, for example, values on how much CO₂ will be emitted when one kilogram of steel is used, but CO₂ emission by steel production will be much smaller in 2030 or 2050. The electricity will also come from renewable energy sources, and the environmental impact of using products will be lower than today.

In light of these changes, “Pre-emptive LCA” is an attempt to quantitatively evaluate the future environmental impact of technologies currently under development to see if they will still be valuable when carbon neutrality is achieved in 2050 (Figure 4). Researching Pre-emptive LCA is one of the major goals of the UTLCA’s establishment.

Figure 4: Pre-emptive LCA

In a society where technology development has progressed and carbon neutrality has been achieved, the composition of power sources, sources of materials, and the ratio of material production through recycling will change significantly. LCA of technologies under development will be conducted assuming such changes.

The Institute for Future Initiative, The University of Tokyo has proposed a long-term vision of Japanese electric power sources toward the year 2050. UTLCA will determine the future power source composition and conduct Pre-emptive LCA based on the proposed long-term vision. In the Pre-emptive LCA, we evaluate not only the environmental impact, but also the amount of electricity and resources that will be required. Otherwise, product development may proceed under the false assumption that green hydrogen, solar power, and storage batteries can be used infinitely in the future.

The Social Cooperation Research Department established by the UTLCA invited companies from a variety of industry sectors, including automobiles, auto parts, chemicals, steel, and automotive recycling. This is because cross-disciplinary discussions are needed on how the manufacturing of steel and plastics will change and how products will be made and used. Also, what kind of mechanisms and technologies will be needed for recycling, including lithium-ion batteries, if electric vehicles become widespread. If new plastics are made from waste plastics, how will they be used separately from the fossil-derived plastics? We must consider these scenarios along the time axis. This is a very complex task, which is why I believe it is worthwhile for universities to do it.

Let’s imagine upstream and downstream of the product.

What is needed to make LCA permeate society?

I believe that consumers play an important role. No matter how many standards and systems are established by the government, no matter how many environmentally friendly products are produced by the producers, if consumers do not concern, the entire social system will not work. I would like to encourage consumers to imagine the life cycles of the things around them.

For example, when you do laundry, you may be concerned about the environmental impact of electricity and water use, but LCA shows that the use of detergent is also a major environmental impact factor. This is because palm oil, which is one of the factors contributing to the decrease of tropical rainforests, is used as a raw material for detergents. This is what it means to know the life cycle.

Even for drinking water, if you buy imported mineral water from a convenience store and drink it, CO₂ emissions are six times higher per 500 ml than if you drink boiled and chilled tap water from a water bottle. This is due to the environmental impact of the production and distribution stages, as well as when disposing of PET bottles as combustible waste (Figure 5).

Figure 5: How to choose drinking water

Drinking tap water from a glass cup has almost zero environmental impact, but buying domestic or foreign mineral water from a vending machine or convenience store and disposing of the plastic bottle as combustible waste emits more than 300 g CO₂.

In addition, despite the high environmental impact of clothing and textiles, recycling methods have not yet been established. Fast fashion’s business model of mass production and mass consumption could lead to mass disposal of clothing. In France, companies have been banned from discarding unsold new clothing since January 2022. We would like consumers to be interested in what is happening upstream, such as what kind of environment sheep are raised in, and how cotton is grown, spun, and sewn. This is not limited to clothing. From an LCA perspective it is best not to over-purchase, but to care for and repair what you buy, use it up, and finally sort it and dispose of it in a way that it can be recycled.

The environmental impact caused by human activities must be contained to the equivalent of one planet. UTLCA hopes to contribute to changing society in this way.

(Reporting and composition by Yuko Inoue)

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