Human&Nature

New Concept English human and nature
Charlie
第二次作业• 13年3月31日
Human Activities and Biodiversity
Benefits
Biodiversity supports ecosystem services including air quality,climate (e.g., CO2 sequestration), water purification, pollination, and prevention of erosion.Since the stone age, species loss has accelerated above the prior rate, driven by human activity. Estimates of species loss are at a rate 100-10,000 times as fast as is typical in the fossil record.Non-material benefits include spiritual and aesthetic values, knowledge systems and the value of education.
Industrial materials
Many industrial materials derive directly from biological sources. These include building materials, fibers, dyes, rubber and oil. Biodiversity is also important to the security of resources such as water, timber, paper, fiber, and food.As a result, biodiversity loss is a significant risk factor in business development and a threat to long term economic sustainability.
Population issues
From 1950 to 2005, world population increased from 2.5 billion to 6.5 billion and is forecast to reach a plateau of more than 9 billion during the 21st century.Sir David King, former chief scientific adviser to the UK government, told a parliamentary inquiry: "It is self-evident that the massive growth in the human population through the 20th century has had more impact on biodiversity than any other single factor."
Overexploitation occurs when a resource is consumed at an unsustainable rate. This occurs on land in the form of overhunting, excessive logging, poor soil conservation in
agriculture and the illegal wildlife trade. Joe Walston, director of the Wildlife
C onservation Society’s Asian programs, called the latter the "single largest threat" to biodiversity in Asia. The international trade of endangered species is second in size only to drug trafficking.About 25% of world fisheries are now overfished to the point where their current biomass is less than the level that maximizes their sustainable yield.The overkill hypothesis explains why earlier megafaunal extinctions occurred within a relatively short period of time. This can be connected with human migration
from wiki。