Chapter 12 Human Impact on Resources and Ecosystems.ppt

Human Impact on Resources and Ecosystems Chapter 12 Chapter Outline Historical Basis of Pollution Resource Utilization Mineral Resources Ecosystem Modification Forests Rangelands Wilderness Aquatic Managing Ecosystems for Wildlife Extinction Changing Role of Human Impact As human population grew, and tools became more advanced, the impact a single human could have on surroundings increased. Environmental modifications allowed larger, dense human populations to arise. Nearly all earth’s surface has been affected in some way by human activity. Historical Basis of Pollution Pollution—Anything released into the environment that affects an organism’s survival and reproduction. Two primary factors affect the amount of damage done by pollution: Size of the population Level of technological development Historical Basis of Pollution When the human population was small, waste products were generally biodegradable. Human-caused pollution is produced when waste is generated faster than it can be degraded, especially as people began to congregate and establish cities. Throughout history, humans fought ecosystem degradation with technology. Short-term solutions. Renewable and Nonrenewable Resources Natural Resources—Structures and processes humans can use, but not create. Renewable—Can be formed or regenerated by natural processes. Soil, Vegetation, Wildlife Non-Renewable—Not replaced by natural processes, or, rate of replacement is ineffective. Minerals, Fossil fuels Costs Associated With Resource Utilization Economic—Monetary costs necessary to exploit the resource. Energy—Energy expended exploiting the resource. Environmental—Environmental effect of resource exploitation (often deferred). Mineral Resources Major form of nonrenewable resource. Distribution is not uniform. Many deposits have already been exploited. North America consumes 30% of world minerals. Steps in Mineral Utilization Exploitation Mining Refining Transportation Manufacturing Recycling of Mineral Materials