Fewer people doesn’t always mean better outcomes for nature—just look at Japan

Since 1970, 73% of world fauna has been lost, while the world’s population has doubled to reach 8 billion. Research shows that it is not a coincidence, but that demographic growth leads to a catastrophic decrease in biodiversity.

However, a turning point in human history is underway. According to UN projections, the number of people in 85 countries will decrease by 2050, mainly in Europe and Asia. By 2100, the human population is in the process of world decline. Some say it will be good for the environment.

In 2010, Japan became the first Asian country to start depopulating. South Korea, China and Taiwan follow closely. In 2014, Italy was the first in southern Europe, followed by Spain, Portugal and others. We call Japan and Italy of “avant-garde countries” because of their role of precursors to understand the possible consequences in their regions.

Given the hypotheses that depopulation could help provide an environmental restoration, we have worked with Yang Li and Taku Fujita colleagues to determine if Japan saw what we have called a “depopulation dividend” of biodiversity or something else.

Since 2003, hundreds of scientific citizens have been collecting data on biodiversity for the monitoring of Japanese government surveillance sites. We used 1.5 million species observations recorded on 158 sites.

These were in wooded, agricultural and peri-urban areas (transitional spaces on the outskirts of cities). We have compared these observations to changes in the local population, the use of land and the surface temperature for periods of five to 20 years.

Our study, published in the journal Natural sustainabilityIncludes birds, butterflies, fireflies, frogs and 2,922 native and non -native plants. These landscapes have experienced the greatest depopulation since the 1990s.

Due to the size of our database, the choice of sites and the positioning of Japan as a vanguard for Northeast Asia, it is one of the largest studies of the gender.

Japan is not Chernobyl

Biodiversity has continued to decrease in most of the areas that we have studied, regardless of the increase or decrease in the population. This is only where the population remains stable is more stable biodiversity. However, the population of these areas will age and decreases soon, putting them online with areas that already see a loss of biodiversity.

Unlike Chernobyl, where a sudden crisis caused an almost total evacuation which stimulated the surprising stories of the fauna rebirth, the loss of population in Japan has gradually developed. Here, a mosaic scheme of the evolution of land use emerges in the midst of communities that still work.

While most agricultural land remains cultivated, some fall into disuse or abandonment, some are sold for urban development or transformed into high landscapes of breeding. This prevents the widespread natural succession of the growth or afforestation of plants (planting new trees) which would enrich biodiversity.

In these areas, humans are agents of the sustainability of ecosystems. The traditional practices of agriculture and seasonal livelihoods, such as floods, planting and harvesting rice fields, managing orchards and tickets and maintenance of properties, are important to maintain biodiversity.

Depopulation can therefore be destructive for nature. Some species thrive, but they are often non-natives that have other challenges, such as drying and suffocation of rice fields formerly damp by invasive grasses.

Vacant and abandoned buildings, underused infrastructure and socio-legal problems (such as complicated succession laws and land taxes, the lack of administrative capacity of local authorities and high demolition and elimination costs) worsen the problem.

Even if the number of Akiya (empty houses, abandoned or abandoned) increases to almost 15% of the country’s housing stock, the construction of new housing continues tirelessly.

In 2024, more than 790,000 were built, due in part to the evolution of the distribution of the population and the composition of households in Japan. In addition to these roads, shopping centers, sports facilities, parking lots and omnipresent convenience stores from Japan. Overall, fauna has less space and fewer niches to live, although there are fewer people.

What can we do?

The data shows the deepening of depopulation in Japan and Northeast Asia. Fertility rates remain low in most developed countries. Immigration provides only a milder short -term landing, as countries are currently providing migrants, such as Vietnam, are also underway for depopulation.

Our research shows that the restoration of biodiversity must be actively managed, especially in the depopulation areas. Despite this, there are only a few re -enact projects in Japan. To help them develop, local authorities could be given powers to convert abandoned land into locally managed community conservations.

Nature exhaustion is a systemic risk for global economic stability. Ecological risks, such as inventory of fish stock or deforestation, need better responsibility for governments and societies.

Rather than spending more infrastructure for a constantly evolving population, for example, Japanese companies could invest in the growth of local natural forests for carbon credits.

Depulation is becoming a global megatend of the 21st century. Well managed, depopulation could help reduce the most urgent environmental problems in the world, including the consumption of resources and energy, emissions and waste and nature conservation. But it must be actively managed for these opportunities to be carried out.

This article is republished from the conversation under a Creative Commons license. Read the original article.