Humans and other species

There are different ways in which humans have become responsible for the disappearance of other species. From this point of view a fundamental responsibility is the impact of agriculture on the world ecology. The conversion to agriculture of the land, that has taken away considerable areas from the forests, the grasslands and the humid environments, has deeply simplified the ancient structure of biomes and ecosystems. Naturally these alterations have had differential results in terms of extinctions in the tropical and subtropical areas where biodiversity reaches its peak, the results of the agricultural conversion of the territory have been much greater than in the higher latitudes. But also industrialization and urbanization have played a key role in the extinction of the species. In particular, in the last three-four centuries, the human population has registered a rate of growth that had never been noted in the past, and anthropization of the natural environments that derived from this and all its consequences in terms of cementing, industrialization and deterioration of the territory, has deeply modified the features, and the ecological quality of the habitats. Another crucial factor in the present loss of biodiversity is to be found in the anthropogenic climate change. The accumulation of greenhouse gas emissions produced by human beings in the atmosphere in fact has produced an increase in the global temperature, that in many regions of the planet is already pointing out severe biological alterations and documented extinction phenomena.
The origin of the extinctions that are being recorded all over the world however, is not very recent. Due (directly or indirectly) to man, many hundreds of animal and vegetable species have become extinct starting 400 years ago. Furthermore it must be taken into consideration that many other species today can survive only because they are bred in captivity or are under the protection of conservation programmes. The IUCN (International Union for Conservation of Nature and Natural Resources) organization cyclically issues a “red list” of the organisms that are threatened by extinction. At present the list includes 12,500 species subdivided into the categories “in critical danger”, “in danger” and “vulnerable”. For example, out of the almost 10,000 species of birds, over 1,000 are classified in one of the three categories indicated above. Which means that more than 10% of the avifauna in the world, has a significant risk of extinction.
However the problem may be even more severe. In fact if on one hand many “vulnerable” organisms can be monitored quite easily nowadays, and therefore effective measures can be carried out in order to protect them, on the other hand there is an entire universe of organisms that cannot be controlled easily that, due to their microscopic size, their habits or for the simple fact that they still have not been discovered, escape any form of assessment of their state of conservation. A precise definition is important because most of the biomass of the planet is probably concentrated in these organisms, which in turn play an indispensible role in the balance of the ecosystems.

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