- Almost 95% of the Earth's surface has been modified by humans.
- Data scientist Hannah Ker has create a map which tracks five categories of human use of land - and the impact they've had.
- With every new use of land, we run the risk of upsetting delicate ecosystems that sustain life on Earth.
- By making smarter decisions around how land is used and what impact it has, we can preserve these ecosystems for generations to come.
View the high resolution version of this map by clicking here.
There is little doubt that human activity has impacted the Earth, but to what extent?
As it turns out, nearly 95% of the Earth’s surface shows some form of human modification, with 85% bearing evidence of multiple forms of human impact.
This map by data scientist Hannah Ker outlines the extent of humanity’s modification on terrestrial land ecosystems.
Measuring the human impact
This map relies on the Global Human Modification of Terrestrial Systems data set, which tracks the physical extent of 13 anthropogenic stressors across five categories.
Human settlement: population density, built‐up areas
Agriculture: cropland, livestock
Transportation: major roads, minor roads, two tracks, railroads
Mining and energy production:mining, oil wells, wind turbines
Electrical infrastructure: powerlines, nighttime lights
Researchers compiled all these stress factors and scaled their impact from 0 to 1. Then, in order to map the impacts spatially, the surface of land was organized into cells of 1 kilometer in length creating “edges” of varying impact.
These impacts are further organized by biomes—distinct biological communities that have formed in response to a shared physical climate.
Digging into the data
Only 5% of the world’s lands are unaffected by humans, which amounts to nearly 7 million km² of the Earth’s land, and 44% (59 million km²) is categorized as low modification.
The remainder of land has a moderate to high degree of modification: with 34% categorized as moderate (46 million km²), 13% categorized as high (17 million km²), and 4% categorized as very high modification (5.5 million km²). This latter category is the most visible on the map, with portions of China, India, and Italy serving as focal points.
Below is a look at how Earth’s various biomes fare under this ranking system:
Out of the 14 biomes studied, the least modified biomes are tundra, boreal forests, deserts, temperate coniferous forests, and montane grasslands. Tropical dry broadleaf forests, temperate broadleaf forests, Mediterranean forests, mangroves, and temperate grasslands are the most modified biomes.
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Dense human settlements, agricultural land uses, networks of infrastructure, and industrial activities dominate the more highly modified biomes. These lands are commonly subject to five or more human stressors simultaneously, threatening naturally-occurring ecosystem services.
What are ecosystem services?
An ecosystem service is any positive benefit that wildlife or ecosystems provide to people, and they can be sorted into four categories:
Provisioning services: This is the primary benefit of nature. Humans derive their food, water, and resources from nature.
Regulating: Plants clean air and filter water, tree roots help to keep soil in place to prevent erosion, bees pollinate flowers, and bacterial colonies help to decompose waste.
Cultural services: Humans have long interacted with the “wild” and it in turn has influenced our social, intellectual, and cultural development. However, the built environment of a city or town separates man from nature and ancient patterns of life. Ecosystems have long served as inspiration for music, art, architecture, and recreation.
Supporting services: Ecosystems contain the fundamental natural processes that make life possible such as photosynthesis, nutrient cycling, soil creation, and the water cycle. These natural processes bring the Earth to life. Without these supporting services, provisional, regulating, and cultural services wouldn’t exist.
A delicate balance
With each encroachment upon habitat, the potential increases for humans to inadvertently upset the careful balance of ecosystem services that have nourished the processes of life on Earth.
As we become more aware of the human impact on the plant, we can make smarter decisions about how our society and economies function—ultimately ensuring that the same ecosystem services are there for future generations.