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Global public goods and nature services: Difference between revisions
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Global public goods and nature services (view source)
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Bedřich Moldan | Bedřich Moldan | ||
By introducing agriculture ten to twenty thousand years ago, man set himself apart from nature radically and separated from it. It was then that people began to create their own human world. Instead of hunting and gathering food, they began to live on crops they grew (predominantly cereals), meat and other products from the animals they reared. Whilst hunters and gatherers were part of nature, that was no longer true of farmers. Each and every field is an encroachment on intact nature: it occupies the space of a former forest, savannah, or other natural formation. The same applies to pastures and all other areas used as means of production by farmers. With their activity, farmers defied nature in a way, as they conducted their activities to the exclusion of the original ecosystems from the very start. Threats to natural resources and the environment occurred when the farmers mismanaged those resources, causing serious disturbances. Environmental devastation accompanied ancient civilisations and it is now generally concluded that it was the reason for the disappearance of some of these civilisations. | |||
The present situation, however, is fundamentally new. People are affecting their environment on a global scale. That is why Paul Crutzen and Eugene Stoermer (Crutzen et Stoermer, 2000) titled the current period '''anthropocene'''. What they implied by this was that humankind has become the decisive force on planet Earth over approximately the last two hundred years (symbolically, the authors put the origins of anthropocene in 1794, when James Watt invented the steam engine). At the onset of anthropocene, Earth had about 800 million inhabitants, of whom only a minor part lived in towns and cities. The urban population increased from about 200 million in 1900 to 2.9 thousand million in 2000, while the number of cities with a population over one million grew from 17 in 1900 to 388 in 2000. Of crucial importance, however, is not only the rapid growth in the Earth’s population but, in the first place, the changing consumption and production patterns combined with the massive power of technology. | |||
The greatest changes, easily observable from outer space, concern the land surface. At the beginning of the period, pastures and fields took up about 12% of the dry land area; it is 37% now, while an entire 50% has been transformed radically by one human activity or another. People use about 40% of the primary biological production of all green plants directly or indirectly, as well as 40–50% of the available sources of freshwater; some of the great rivers are subject to such heavy exploitation that they fail to flow to the sea for several months each year (Hoang Ho). Man affects the climate substantially, above all, by producing greenhouse gases (the atmospheric CO<sub>2</sub> and methane concentrations have increased by 40% and 100%, respectively); man has reduced the stratospheric ozone layer massively; and changed the chemical composition of the entire troposphere (such as by long-distance pollutant transmission). The biogeochemical cycles of the principal nutrients have changed: the anthropogenic nitrogen flow is at 150% of the natural flow; it is at 200% and 460% for sulphur and phosphorus, respectively. Heavy metals and artificially produced organic substances have been mobilised; they often have very long life and physiological effects. | |||
The current period of anthropocene has completed the process of gradual '''human domination '''of planet Earth. The domination is now nearly total. As Vitousek et al. put it, ‘…it is ever more obvious that we live on a man-controlled planet.’ (Vitousek et al., 1997). | |||
At the same time, this gives us an opportunity to overcome the fundamental dissension, disunion between people and nature, initiated by the appearance of the early farmers. Before them, man was part of the natural world, one of the species competing with others, finding its ecological niche. The situation has reversed: nature has become part of the human world. Planet Earth is a human planet: there is a place and reason for nature, wild and cultivated to any degree, in it but it is essentially only a place that humans have assigned it. | |||
==Ecosystem Services == | ==Ecosystem Services == | ||