Biosphere

The biosphere is the global sum of all ecosystems, encompassing all living organisms and their interactions with the air, water, and rocks that make up Earth’s lithosphere, hydrosphere, and atmosphere. It extends from high in the atmosphere to the deepest subsurface environments where microorganisms persist, and from polar seas to tropical soils.

Life in the biosphere is organized into ecosystems that transfer energy and matter through food webs and biogeochemical cycles. The sun powers photosynthesis, which supports primary production and, in turn, all higher trophic levels. Major cycles—carbon, nitrogen, phosphorus, and water—are driven by biological activity and microbial processes, shaping climate, soil fertility, and nutrient availability.

There is no single boundary for the biosphere. Its extent is defined by the presence of living systems and their interactions, which occur across oceans, forests, grasslands, deserts, soils, and sub-surface habitats. Microbes inhabit rocks kilometers underground and communities persist in extreme environments, illustrating the biosphere’s wide reach.

The concept developed in the early 20th century with contributions from biogeographers Vladimir Vernadsky and Eduard Suess, and it gained broader attention with the Gaia hypothesis, which proposes that life influences planetary conditions. The biosphere is studied in Earth system science, geobiology, and ecology.

Human activities increasingly influence the biosphere, with climate change, habitat loss, pollution, and overexploitation altering biodiversity and ecosystem services such as food, water purification, climate regulation, and cultural value. Conservation and sustainable management seek to maintain biospheric integrity and resilience.