春雨直播app researchers answer questions on 21 GX (Green Transformation) topics from their specialist viewpoints. Through questions that cannot simply be brushed off as someone else’s concerns, take a peek into GX and our world of research.
Q16. Is sharing really good for the environment?
All kinds of shared services are now available, but will they cut CO2 if we use them?Answered by Kiyo Kurisu
Associate Professor,
Environmental Engineering
Evaluating environmental impact “from the cradle to the grave”
Recent years have seen the emergence of sharing services for all kinds of items, from bicycles and clothing to food. However, such services can only have a positive impact on the environment if we understand what happens to the products involved from their production to disposal and then proceed to use them effectively. For instance, using a car-sharing service might not be good for the environment if the same journey was previously made on foot. Likewise, if sharing means that an item has to be produced and thrown away in bigger amounts than before, the resultant increase in consumption will only increase the burden on the environment.
The environmental burden of an item being shared can be quantitatively evaluated with a life cycle assessment (LCA), which calculates the CO2 emitted “from the cradle to the grave” — all the steps from the acquisition of the raw materials for its production through to its final disposal. An LCA not only calculates the total emitted CO2, but also tells us which steps of the overall process are placing the biggest burden on the environment. For example, the running of a car has a far greater impact on the environment than its production and disposal, indicating that dealing with fuel consumption is vital for cutting a car’s CO2 emissions. On a mile for mile basis, therefore, it is better for the environment to share a relatively new, fuel-efficient car such as an electric vehicle (EV) rather than to just continue using an old car for many years. The same applies to household electrical appliances. It is more environmentally friendly to buy a new appliance rather than continuing for several years to use an older one with a poorer energy efficiency.
Other items, such as umbrellas or furniture, emit almost no CO2 during their use. In these cases, the focus should be on cutting the CO2 emitted during their manufacture and disposal. The environmental burden associated with the production and disposal of an umbrella that will be rented out is likely to be higher than that of a cheap plastic one. That burden can be offset, however, if it gets used by a sufficient number of people. Similarly, as an environmentally friendly alternative to disposable plastic bags, many shoppers now use their own “eco bag” or other type of reusable bag. However, such bags need to be used at least 100 times before they can bring any benefit to the environment.
Attitudes towards sharing differ by country
While sharing services have grown as a new consumption model all over the world, attitudes about the joint use of things can differ from country to country. In my lab, we have investigated differences in consumer attitudes between Switzerland and Japan. Whereas most Japanese are open to the concept of renting sports goods or formal wear that have already been used by others, the Swiss strongly want to possess such items as their own. Also, while the limited storage space in their homes makes item sharing attractive to the Japanese, the Swiss place great importance on the quality of the items that are offered for sharing.
I have conducted various kinds of research on the effects of climate change over the years, and one of the biggest themes I have tackled throughout is how to effectively communicate information that will lead to changes in human behavior. To try to address this, I have even produced educational tools, such as a sugoroku board game, that teach LCA. I hope that my research will help everyone to become more aware of climate change and bring about changes in their behavior.
