- Stahuj zápisky z přednášek a ostatní studijní materiály
- Zapisuj si jen kvalitní vyučující (obsáhlá databáze referencí)
- Nastav si své předměty a buď stále v obraze
- Zapoj se svojí aktivitou do soutěže o ceny
- Založ si svůj profil, aby tě tví spolužáci mohli najít
- Najdi své přátele podle místa kde bydlíš nebo školy kterou studuješ
- Diskutuj ve skupinách o tématech, které tě zajímají
Studijní materiály
Zjednodušená ukázka:
Stáhnout celý tento materiálCURRENT ECOLOGICAL ISSUES
A. Development of people-nature relationship
At the beginning of the human existence, people lived just in those parts of world where they had suitable conditions for life. People, hunters-gatherers, were a part of nature. They were adapting to the changing environment as well as the animals do. However gradually, they started to change the environment instead and adapt the nature to fit them. Rapid growth of population, development of knowledge, inventions in technical, production and energy fields, then lead to even bigger change in the character of original biosphere.
Deforestation, pastoralism, impropriate cultivation of soil, desiccation or irrigation, intended and unintentional spread of plant and animal species caused the change of natural ecosystems and broke the ecological equilibrium on many parts of the Earth. People created “new nature” with intensive agriculture, forestry, industrial areas, heavy transport network and build-up areas. Usage of natural resources speeded up as well as accumulation of waste materials and pollution of atmosphere, water and soil. In big part of the Earth, nature was replaced by technosphere (= place of all kinds of human action – social, labor, cultural, recreational sector). When creating new environment, people often get into conflict with the nature. Human influence on the nature is not longer local, but it is global, so these newly-created problems must be solved in global scale (that is why is the solution so complicated).
B. Growth of human population
In antiquity and middle ages, the population was quite low. It was limited by amount of food, epidemics of infectious diseases and other factors. From the 19th century, the population started to grow as a result of development in agriculture and technologies and scientific inventions. At the beginning of A.D., the world population was about 100-200 millions people, at the beginning of 20th century it was 1,5 billion people, in 1970 it was 3,5 billion people, today it is more than 6 billions people and according to predictions, by 2080, there will be more than 10 billion people on the Earth.
C. People as farmers
People’s main aspiration – growing monoculture = growing only one species of plant on certain place (no other plants can limit it, only for people – no other animals can eat it) → great effort to keep these conditions
→ Herbicides – chemical substances which are supposed to limit the growth of weed
→ Pesticides – chemical substances which are supposed to protect the plant against animals which would eat it
BUT → only more and more problems
→ weed became resistant against herbicides, some herbicides toxic for predators → more pests → more pesticides needed
→ pesticides can kill even other animals, cause water pollution
Also by planting only one species, divesfication is affected → quicker spread of epidemics (normally, the other plants on field form a barrier against spread of diseases BUT in monocultures, there is no such a barrier)
-bigger the energy exerted → bigger intensity of cultivation → bigger the human influence on nature → bigger change between original and newly-created environment
-today’s tendency – biologication of agriculture = preferring such processing and technologies so that they do not cause permanent damage to the original environment
D. People as producers and consumers
Environment influenced by two main sectors of human action:
Production (industry, building, extracting of raw materials, energy production)
Non-productive actions (transport, accumulation of waste products, recreation)
Rapid development → bigger need of natural resources, breaking ecological balance, pollution × more comfortable life (!!!only in more developed countries!!!)
Comparison of developed and developing countries
One billion of world population lives in poverty, malnutrition, diseases and despair
Developing countries – life expectancy 50 years; developed countries – life expectancy 70 years
Developing countries – child mortality 200 deaths per 1000 births; developed countries – 10-20 deaths per 1000 births
In developing countries, there is 200x bigger probability that a women dies during labor than in developed ones.
40 000 children die every day because of malnutrition
E. Global problems of today’s world
Techno-economic problems
Vloženo: 8.07.2011
Velikost: 52,50 kB
Komentáře
Tento materiál neobsahuje žádné komentáře.
Mohlo by tě zajímat:
Skupina předmětu BI - Biologie
Podobné materiály
- AJ - Anglický jazyk - Current problems in society
- BI - Biologie - ECOLOGY,ECOLOGICAL TERMS,ECOSYSTEMS
- AJ - Anglický jazyk - Enviromental issues
- AJ - Anglický jazyk - Enviromental issues
- AJ - Anglický jazyk - Environment and environemntal issues
- AJ - Anglický jazyk - Global Issues
- AJ - Anglický jazyk - Social Issues. checked
- AJ - Anglický jazyk - Social issues
Copyright 2024 unium.cz