6.1 A CHANGING LANDSCAPE
To protect Earth's resources, we need to understand how humans interact with the biosphere. We will have to learn about energy flow, chemical cycling, climate, and population limiting factors.We must also have to understand how scientific models can be used to make a prediction on a complex system. We humans are like all organisms, we do participate in the food web and chemical cycles. Because we depend on ecosystem goods and services, we must be aware that our activities can change local and global environments. Among human activities that affect the biosphere are hunting and gathering, agriculture, industry, and urban development.
Our ancestors got their food from hunting and gathering. Even though hunting may sounds harmless, but even these hunters and gathers change the environments. Excessive hunting can cause extinction and thus a change in the food web. After human learned how plants grew, humans began the practice of farming or also called as agriculture. With a stable and predictable food supply, humans began to gather in larger settlements rather than travel in search of food. As farming advance, machines was to use to help with cultivation. Monoculture in which large fields are planted with a single variety year after year.
Even though there were agricultural advances in the middle of the 20th century, there were food shortages in many parts of the world. Modern agricultural techniques were introduced, such as monoculture and the use of chemical fertilizers, this effect was called the green revolution. Even though hunger is still a major problem, the green evolution was a great change that helped many people stay full.
While increasing world food supplies, modern agricultures has created ecological challenges. Large scales monoculture can lead to pest problems. With a large amount of food, the population of pests will increase. Due to this, farmers may use pesticides. Unfortunately, these chemicals can damage beneficial insects, contaminate water supplies, and accumulate in the environment. A second challenge is finding enough water for irrigation.
Human society and its impact on the biosphere were transformed by the industrial revolution. This revolution gave light to homes and clothes for many people to wear, but the cost is that we must use fossil fuels, coal, oil and natural gas. For many years, factories discard wastes from manufacturing. Industrial processes pollute air, water, and soil. Human communities produce wastes that must be disposed of. Also human communities need farmland and natural habitats.
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