It seems tough to continue living like this for another 25 years

The second week of the new semester has ended, and I started bouldering yesterday. I climbed a gimmick wall built by a German person with Japanese, Korean, and Mexican people.

Thanks to the special training I did climbing banyan trees since kindergarten, I managed to clear most of the levels up to level 4 out of 8 on my first day, making me an intermediate climber. I am very happy about this. This is all thanks to everyone.

Now, this time, I am looking at a paper published in April 2025 that applies planetary boundaries to individual actions and concretizes their impact on the environment.

To quickly review planetary boundaries, they are a concept that indicates nine threshold values for the Earth to continue functioning safely for humanity. According to the latest 2023 research, we have already exceeded six boundaries, making it clear that our lives are placing a heavy burden on the Earth.

In this paper, based on the lives of people in Denmark, we concretely clarified the impact our daily actions have on the global environment.

Modeling of Danes

Now, in this paper, we selected four major activities from the life of a typical Dane that consumers can relate to.

The four are as follows.

• Mobility
  -> commuting, travel, cars...
  

• Housing
  -> house size, electricity, heating, lighting...
  

• Consumer goods (consumables)
  -> electronic devices, laundry, clothes, showers, drinking water...
  

• Food
  -> type (vegetarian, vegan, etc.), organic, fresh, frozen, milk...

And, they defined the activity level for each over one year. For example, commuting 22km per day, buying 10kg of clothes per year, or drinking 117kg of milk per year.

They investigated how continuing those activities at current levels for 25 years until 2050 would affect sustainability.

Environmental impact in daily life

I have created six indicators based on planetary boundaries, and the following is the result of examining whether the Danish population is effectively utilizing their environmental budget per capita.

The categories from the left are functional biodiversity, climate change, marine eutrophication, land occupation, resource use, and water consumption.

The bluish 'individual budget' at the bottom is the level that should be maintained, but everything except water consumption is way over the environmental budget. Regarding the budgets for biodiversity and resource use, they exceed 1000%.

Let's take a quick look at the four main activities.

• Food alone exceeds the environmental budget in four categories
  → Functional biodiversity 536%, climate change 143%, land use 152%, resource use 138%
  

• Transportation also exceeds the budget in three categories on its own
  → Functional biodiversity: 206%, climate change: 145%, resource use: 454%
  

• Housing also exceeds the budget in two categories on its own
  → Climate change: 215% and resource use: 142%
  

• Consumer goods have a small overall percentage, but still account for a large consumption of the environmental budget
  → Water consumption: 13%, resource use: 232%

As you can see, there is an outrageous excess. It is particularly clear how high the burden of modern dietary habits is. It is difficult to be conscious of this on a daily basis, but when it is shown in figures like this, we are confronted with how unsustainable our lives are. This is an important reflection.

Now, let's take a concrete look at what kind of actions can reduce environmental impact.

Daily eco-activities you should know about

Of course, just because you are working on it as an individual does not mean that good results will be achieved immediately, but it is an interesting point that it is surprisingly possible to keep environmental impact within an individual's environmental budget.

Transportation

• Switching from a gasoline car to a small electric vehicle reduces the climate change budget from 129% to 50%
  → However, resource use increases from 67% to 230%
  

• When commuting, switching from a gasoline car to an electric motorcycle reduces climate budget consumption from 62% to 5%
  

• Air travel consumes 64% to 103% of the climate budget depending on the average annual flight distance (approx. 8700 km)

Housing

• Living in an average new home today consumes 115% to 121% of the resource budget.
  

• Switching from an oil boiler to heat pump heating reduces the climate change budget from 82% to 12%.
  → Resource budget consumption increases from 10% to 25%.
  

• Installing solar panels reduces the climate change budget from 17% to 4%.

Consumables

• Owning a television accounts for 188% of the resource budget, and owning a laptop accounts for 65%.
  

• Reducing shower time from 10 minutes to 5 minutes can reduce water budget consumption from 20% to 10%.
  

• Laundry temperatures and the use of reusable bags do not show significant changes in any category.

Food

• An omnivorous diet accounts for 384% of functional biodiversity, 101% of climate change, and 149% of land occupation.
  

• Switching to a vegetarian or vegan diet reduces climate impact to 33% and 22%, respectively.
  

• Milk consumption accounts for 84% of the functional biodiversity budget and 28% of the land occupation budget.
  → Replacing it with oat milk significantly reduces these to 2% and 1%, respectively.

I think the food aspect is what really deserves attention. In Germany, I have never seen a restaurant that doesn't offer vegetarian or vegan options, but it is still quite rare in Japan. This article about dietary habits is also interesting, so I will write about it later.

While researchers state that a shift to a simpler lifestyle is essential, they also note that changes across society as a whole, such as environmentally friendly production systems through technological progress and the expansion of public transportation, are also important.

Personally, as I saw in the 50-year literature review on the bioeconomy , research on individual-level consumption behavior is quite weak, so I would like to see more such research in various countries and have local governments or regions put together something like a living guideline.

Summary

In short, the current state of transportation, housing, consumables, and dietary habits is simply not sustainable. I have summarized the points briefly below.

• Review transportation methods: Reduce car usage and utilize public transportation, bicycles, or walking.

• Choose energy-efficient appliances: Select appliances with high energy-saving performance and use them carefully for a long time.

• Improve dietaryhabits: Reduce meat consumption and shift to a diet centered on vegetables and fruits.

• Cherish your belongings: Avoid disposable items and choose things that can be used for a long time. Actively engage in recycling.

Let's enjoy the process.

References

• Teddy Serrano, Samir Meramo, Anders Bjørn, Michael Hauschild, Sumesh Sukumara, Morten O.A. Sommer, Communicating the environmental impacts of individual actions in the context of Planetary Boundaries, Sustainable Production and Consumption, 2025, ISSN 2352-5509, https://doi.org/10.1016/j.spc.2025.03.021.