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Global Issues BIOLOGY CH 6 The Effect of Human Activity How do our daily activities affect the environment? Environmental Problems CAUSED by HUMANS Rapid population growth More humans = more needs We Need Food, Water, Shelter All resources come from the environment Pollution Humans are increasing the levels of pollution in the environment Causes cancer in humans and animals Leads to the extinction of many species Atmospheric Pollution Increase in carbon dioxide pollution caused by burning fossil fuels Global temperatures are increasing Polar ice caps are melting and Sea levels are rising Holes in atmosphere are allowing in more ultraviolet light leads to mutations (skin cancer) Oceanic Pollution Eutrophication occurs when excess nutrients run off into the environment Examples: Chemical and oils spills Biological Magnification Occurs when toxic chemicals accumulate in the tissues of organisms Example: (DDT) dichlorodiphenyltrichl oroethane is a pesticide used to kill insects, but has negative effect on birds and other organisms The Value of Biodiversity Why is biodiversity important? The Value of Biodiversity • • Total of all the genetically based variation in all organisms in the biosphere is called biodiversity Types of biodiversity: o Ecosystem diversity (variety of habitats & communities) o Species diversity (1.8 million species & 30 million yet to be discovered) o Genetic diversity (genes present in a species) Problem: Biodiversity Crisis More species are going extinct now than in the past 100 thousand years HUMANS Threat BIODIVERSITY By: • Altering habitats Deforestation & Habitat fragmentation (clear land for farming, housing decreases biodivesity) HUMANS Threat BIODIVERSITY By: • Overharvesting killing wild organisms at a rate greater than the population can replenish HUMANS Threat BIODIVERSITY By: • Introducing invasive species nonnatives species compete for food and space HUMANS Threat BIODIVERSITY By: • Releasing pollution into food webs biological magnification (Pesticides & Acid Rain) • Trying to “fix it” Farmers using less pesticides Alternative energy sources are being looked at. HUMANS Threat BIODIVERSITY By: • Contributing to climate change global warming Trying to “fix it” • Need to buy cars with good gas mileage, find alternative energy sources, protect forests (natural CO2 absorbers) HUMANS Increase Biodiversity • • • Wildlife protection of species Researching the needs of organisms and their interactions Preserving forest and wetland habitats and ecosystems Re-introduction of a native species will increase biodiversity Sustainable Development What is the relationship between resource use and sustainable development? Sustainable Development • Using natural resources in a way that does not cause long-term environmental harm is called sustainable development • causes no long-term harm to the soil, water, and climate on which it depends • consumes as little energy and materials as possible. • flexible enough to survive environmental stresses like droughts, floods, and heat waves