This is the 300th article in this Pick Up series. This time, we would like to introduce a paper that summarizes the concept of the Anthropocene, which has become a common topic in recent food system discussions.　

The paper published in the journal Earth’s Future provides an overview of the Anthropocene concept. It was first mentioned in 2000 by Paul Crutzen, a Dutch meteorologist and atmospheric chemist who was awarded the 1995 Nobel Prize in Chemistry for his work on the ozone hole, starting with the argument that human impact on the Earth in modern times was sufficient to create a new geological era. This concept took root in the Earth system sciences, where new definitions were being developed for the global change processes that would gradually alter the conditions typical of the Holocene.

According to the article, the Anthropocene was initially associated with the effects of human activity in the late 18th century, after the British Industrial Revolution, when rising concentrations of atmospheric greenhouse gases, particularly carbon dioxide and methane, began to occur. However, with further research, the Anthropocene seems to be more commonly associated with the "Great Acceleration" of the mid-20th century since 1950, when the effects of rapid socioeconomic changes gradually began to have a significant impact on Earth system trends.

In the two decades since 2000, this concept has spread not only to the earth sciences, but also to the social sciences, arts and humanities. As a result, depending on the discipline, the Anthropocene has been interpreted in a broader sense than Crutzen originally intended, going back thousands of years before humans began to affect the environment. The paper argues that it is appropriate to go back to the geological ages that define the Anthropocene, especially in light of the rapid increase in the atmospheric concentration of carbon dioxide and the acceleration of the nitrogen-phosphorus cycle, and to use 1950 as a starting point, but stresses the importance of discussions that transcend academic disciplines.

As mentioned in a previous article, during the Anthropocene, the global food system has been a major factor in the loss of biodiversity, land use conversion, depletion of water resources, and pollution of terrestrial and aquatic ecosystems.The current global population is estimated to be 10 times the size of all wild mammals in terms of weight, and if we add livestock, wild animals account for only about 4% of all mammals on earth. Through the anthropogenic selection of harvests and chemical pollution processes involved in the reproduction of crops, livestock, trees, and microorganisms, humans are directly and indirectly determining the survival and demise of species, modifying the biosphere that covers the planet, and influencing the Earth system and its biosphere at a planetary level.　

Under the Paris Agreement, the international framework for climate change adopted in 2015, each country will review its Nationally Determined Contributions (NDCs) for greenhouse gas emission reductions and climate change adaptation every five years. The timing is set for 2021. This is an opportunity for policy makers to present solutions that can reduce greenhouse gas emissions from the perspective of a "food systems approach" and to set ambitious targets.

JIRCAS aims to contribute to efforts to make the global food system sustainable through the development of science and technology that can contribute to land use change and climate change adaptation at the food production level for developing countries. As an example of our efforts, two proposals by JIRCAS researchers have been provisionally selected for FY2021 SATREPS (Science and Technology Research Partnership for Sustainable Development) project.

The Anthropocene is a hypothetical geological era following the Holocene, which was proposed as the starting point for humans to have a significant impact on the Earth's geology and ecosystems. The impacts include, but are not limited to, anthropogenic climate change (global warming).

Reference
Jan Zalasiewicz et al, The Anthropocene: Comparing Its Meaning in Geology (Chronostratigraphy) with Conceptual Approaches Arising in Other Disciplines, Earth's Future (2021). https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020EF001896　

Contributor: IIYAMA Miyuki (Director, Information Program)