An ecological footprint quantifies humanity’s demand on the planet’s natural resources. It measures the biologically productive land and sea area required to produce resources and absorb waste. This system indicates human impact on the environment, translating resource categories into global hectares (gha) for comparability.
Energy Resources and Carbon Emissions
The consumption of energy resources, particularly fossil fuels like coal, oil, and natural gas, forms a substantial part of the ecological footprint. Burning these fuels for electricity, transportation, and industry releases carbon dioxide and other greenhouse gases. The “carbon footprint” measures these emissions, representing the area needed to absorb this waste.
Globally, the carbon footprint has been the fastest-growing component of the overall ecological footprint, reflecting humanity’s heavy reliance on carbon-intensive energy sources. The land required to sequester these emissions is typically forest land, highlighting the dual demand on forests for products and waste absorption.
Activities such as driving, heating homes, and manufacturing contribute to the carbon footprint. Reducing carbon emissions through renewable energy, improved efficiency, and decreased reliance on fossil fuels is a primary strategy for lowering the overall ecological footprint.
Land-Based Biological Resources
Productive land areas provide food, fiber, and materials, directly contributing to the ecological footprint. This category includes cropland, grazing land, and forest land, each with distinct purposes.
Cropland represents areas used to grow agricultural products, including food, livestock feed, and fiber. Its footprint is calculated based on the area needed to produce harvested quantities at world-average yields. This highly productive land is often under pressure from urbanization.
Grazing land refers to grasslands supporting livestock farming for meat, dairy, hides, and wool. The demand on grazing land is determined by the feed required for animals. Forest land accounts for the area needed to supply timber, paper, and fuelwood, and to absorb carbon dioxide emissions.
Aquatic Biological Resources
Resources from oceans, lakes, and rivers form part of the ecological footprint, primarily through fishing grounds. This reflects the productive marine and freshwater areas needed to sustain aquatic species harvesting. The demand for seafood, including fish and shellfish, contributes to this footprint.
The fishing grounds footprint is calculated based on the annual primary production required to support all harvested aquatic species, including wild-caught fish and aquaculture products.
The environmental impact of seafood varies by species and fishing methods. While certain methods like heavy trawling can be fuel-intensive, wild seafood generally has a lower carbon footprint compared to red meat, cheese, and poultry, and requires virtually no fresh water or land.
Built Environment Resources
The built environment contributes to the ecological footprint by accounting for land occupied by human infrastructure. This includes areas covered by buildings, roads, cities, and other artificial structures.
This land is considered consumed because it is converted from natural ecosystems or agricultural production. The footprint is based on the area covered by infrastructure like houses, industrial structures, roads, and reservoirs. This conversion means these areas are no longer available for original ecological functions, such as supporting biodiversity or growing crops. Human settlements frequently develop in fertile areas, often replacing productive cropland.