2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Agricultural land in the province of Valencia, Spain.
Archaeologists estimate that land use changed landscapes and terrestrial ecosystems three thousand years ago, according to Science. By this time, most of the ancient societies in Eurasia, both Americas and Africa had changed from hunting and gathering to agriculture, which entailed significant anthropogenic changes.
Hunter-gatherers began to change the landscapes and ecosystems of the planet at the end of the last ice age. This process accelerated after the emergence of agriculture and the emergence of settlements. The use of agricultural land entails changes in the environment, including the destruction of forests, soil erosion, a decrease in the number or complete disappearance of animal and plant species, and climate change due to greenhouse gas emissions (1, 2). However, current models that assess how land use changed in antiquity are often inconsistent with each other, as they lack archaeological and paleoecological data.
Therefore, archaeologists and anthropologists from Germany, the United States and the United Kingdom in 2018 created the ArchaeoGLOBE project, the goal of which was to bring together experts to assess land use and the impact of agriculture on landscape and ecosystems over the past 10 thousand years. The project ran from January to September 2018. During this time, the organizers divided the continents (except Antarctica) into 146 regions and collected estimates of 255 archaeologists who conduct research in different parts of the planet. Scientists completed 711 questionnaires for specific regions and periods of time. In them, they divided land use into types, including intensive or extensive farming, livestock raising, hunting, gathering, fishing, and estimated the percentage of land use. As a result, the organizers of the project collected expert assessments for the period from 10 thousand years ago to 1850 (the largest number of them occurred at the end of the old - beginning of the new era), and conducted a global assessment of land use during this time.
It turned out that ancient people significantly changed landscapes on all continents already three thousand years ago. By this time, agriculture had replaced hunting and gathering in more than 63 percent of the regions. Most of the animals were already domesticated by humans between 4,000 and 8,000 years ago. Three thousand years ago, animal husbandry existed in most societies of Eurasia, the Americas and Africa (in 64 regions), and the inhabitants of 75 regions by this time were engaged in extensive agriculture. It is characterized by an increase in yields not due to new technologies, but as a result of the expansion of sown areas. In arid regions and in the far north, where farming was impossible, people raised domestic animals.
Extensive agriculture 10 thousand years ago - 1850
“While the current rate and magnitude of anthropogenic change is much higher than in the distant past, the long-term cumulative change that early farmers caused is much higher than many imagine,” said study author Andrea Kay of Queensland. university. "Even small-scale agricultural production can cause global change when viewed on a large scale and over time."
The authors conclude that they have carried out a detailed reconstruction of regional land use, which may help to create a more accurate global model of anthropogenic impact. With its help, we will be able to understand how agriculture and the emergence of cities influenced environmental changes, including climate change.
According to a number of scientists, the anthropogenic impact on the environment in the past few decades has become so serious that they should be considered the beginning of a new geological era, the Anthropocene. Read more about it in our material "A man passes by as a master."