The biocapacity of an ecosystem is a measure of how much it can produce, such as natural resources, and how well it can absorb and filter materials like carbon dioxide from the air.
Biocapacity is used with the ecological footprint to show how humans affect the environment. Both tools were created by the Global Footprint Network and are used in studies about sustainability worldwide.
Biocapacity is measured in global hectares per person, which means it depends on the number of people living in an area. A global hectare is a unit that represents the average productivity of all productive land and water areas on Earth in a given year. This is because not all land and water areas produce the same amount of resources. Biocapacity is calculated using data from the United Nations about population and land use, and it can be reported for different areas, such as a city, country, or the entire world.
For example, in 2016, Earth had about 12.2 billion hectares of productive land and water areas. When this number is divided by the 7.4 billion people living on Earth that year, it gives a biocapacity of 1.6 global hectares per person. This number includes areas where wild species live and use space that humans also need.
Applications of biocapacity
An increase in the world's population can lead to a decrease in biocapacity. This happens because Earth's resources must be shared among more people, leaving less to meet the needs of a growing population. Today, this issue can sometimes be addressed by using resources from other areas. However, as demand for resources continues to rise, resources may eventually run out, which could cause ecosystems to collapse. A biocapacity deficit occurs when the ecological footprint of a population exceeds the biocapacity of the environment it lives in. "Global biocapacity" refers to the total ability of ecosystems worldwide to support ongoing activities and changes. A biocapacity deficit can arise from three causes: overusing local ecosystems ("overshoot"), relying on resources imported from other regions, or using resources from shared global areas. According to the Global Footprint Network, in 2016, humans used resources equal to 1.7 Earths. More recent data shows that by 2023, human demand exceeded Earth’s regenerative capacity by about 75%, equivalent to using the resources of 1.75 Earths.
The main cause of global ecological overshoot is carbon dioxide emissions from burning fossil fuels. Additional challenges, such as greenhouse gases, climate change, and ocean acidification, can worsen the problem. The term "1.7 Earths" means that renewable resources are being used faster than they can be replaced. This means it would take one year and eight months for Earth to regenerate the resources humans use in one year, including absorbing all waste produced. Instead of using one year’s worth of resources each year, humans are consuming resources that should last for one year and eight months.
If this issue becomes severe, protected areas may be created to help preserve ecosystems. Awareness about declining resources includes recognizing the importance of agricultural land, forests, and rangelands. Comparing biocapacity with the ecological footprint can show whether a population, region, or country is using resources within its available supply. The study of biocapacity and ecological footprint is called Ecological Footprint Analysis (EFA).
Biocapacity is also influenced by the technology used in a given year. While new technologies may change how resources are used, it is unclear whether they are beneficial or harmful. Technology affects how resources are supplied and demanded, which in turn changes biocapacity. For example, using corn stalks for ethanol production makes them a useful resource, increasing the biocapacity of corn fields.
Environmentalists have developed tools called ecological footprint calculators to help individuals determine if their resource use exceeds what is available in their population. These results are then used to assess how much a person contributes to or reduces sustainable development.
In general, biocapacity refers to the amount of resources available to a population at a specific time (supply), while the ecological footprint measures the environmental demand of a region. Biocapacity helps determine how human activities impact Earth. By measuring land productivity (the resources available for human use), biocapacity can predict and analyze the effects of human consumption on ecosystems. The biocapacity of an area is calculated by multiplying the physical area by the yield factor and an appropriate equivalence factor. It is usually expressed in global hectares (gha). Since global hectares convert human consumption like food and water into a measurable unit, biocapacity can be used to determine Earth’s carrying capacity. Because economies rely on natural resources, biocapacity can also help assess human capital.