Biosphere

Definition

The biosphere, or ecosphere, is the overall globally interacting ecosystem and environment of the Earth system, where life exists; that is, the outer litho-, pedo-, hydro-, atmo- and lower stratosphere. It provides and maintains most basic conditions of all life on Earth. Ecologically, it is the global biota and biocoenosis (as defined by de Chardin) or the sum of all organisms and their inhabited environment with which they interact and in which they form (and which may meanwhile be maintained by human intelligence—from geo- over bio- to noosphere, as per Vladimir Vernadski). Additionally, it may be a self-regulating “organism” itself, avoiding extremes for the benefit of life (the Gaia hypothesis of James Lovelock). Naturally, it is the global, dynamically stable, but nevertheless fragile ecosystem comprising all biodiversity with their biological functions (photosynthesis, respiration, decomposition, matter cycling) and vitally important local and global (sub-) ecosystem key processes, mechanisms, and services, such as (a) provision of water and food; (b) support of material cycling, pollination, and dispersal; (c) regulation of climate and disease; and (d) cultural services. The coverlike biosphere system around the Earth is not fully closed but basically determined by external cyclic solar energy and its transformation.

Conditions and Hazards

The fragile, temporarily balanced biosphere conditions are influenced by both natural processes and anthropogenic activities, which set the natural order increasingly at risk. Disturbances of the sensitive complex network interactions and the present energy, element, and information balance result in a spatiotemporal global biosphere change. All life forms have limited ecophysiological niches and depend on suitable conditions where their specific needs for survival are fulfilled. However, natural and anthropogenic hazards and changes in and of the biosphere affect many aspects of life. Despite the biosphere's enormous dimension, the buffer capacity and self-healing mechanisms against disastrous alterations are limited. Resource overexploitation, land-use change, deforestation and emissions of abundant fatal chemicals, genetically engineered organisms, or electromagnetic and radioactive radiation can cause ground, water, and air pollution; mutations, diseases, and death; biodiversity and ecosystem service loss; subsequent amplified feedback; and even global disasters. Some biosphere hazards and harms appear immediately, can decline, and are partly reversible or could be simply switched off. Others can cause delayed long-term reactions (e.g., xenobiotica, greenhouse and ozone-depleting gases) and/or multiply themselves and/or get permanently out of control (e.g., living engineered organisms, atomic technology, resistant toxic chemicals, diseases). Biosphere changes can affect, for example, health and life directly and promptly (toxic chemicals) or indirectly and delayed (climate change or cancer). Disturbances and/or effects can be local, regional, or global and specifically or generally effective, (non)reversible, accumulative, or synergetic. Like globalization, pollution and hazards do not stop at political frontiers, and regions of suffering are often different from those of origin. The serious risk and extent to which the natural biosphere and its organisms, food webs, and matter cycles have already suffered under human impact are reflected by the numerous international environmental agreements concerning, for example, oil pollution, radioactivity, long-range transboundary air pollution, greenhouse gases, or biosafety. For example, nearly 100 chemicals destroying the ozone layer are regulated alone by the Montreal Protocol. Many hazards depend on nonsustainable lifestyles and politics and underlie global and individual human responsibility—a fact that should be pointed out by researchers and educators of global studies across disciplines.

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