2 The Effect of Human Activity How do our daily activities affect the environment?
3 Living on Island EarthLike all organisms, humans affect the environment when we obtain food, eliminate waste products, and build places to live.Human activity has altered roughly half of all the land that’s not covered with ice and snow.Might be reaching carry capacity at 7 billion.
4 AgricultureModern agricultural practices allowed farmers to double world food production over the last 50 years.Monoculture, is the practice of clearing large areas of land to plant a single highly productive crop year after year.
6 Industrial GrowthThe conveniences of modern life require a lot of energy to produce and power.Industries have traditionally discarded wastes from manufacturing and energy production directly into the air, water, and soil.
7 How can we prevent the overuse of resources? Sustainable Development
8 Environmental science … can help us avoid mistakes made by past civilizations. The lesson of Easter Island: people annihilated their culture by destroying their environment.
9 Sustainable Resource Use Using natural resources in a way that does not cause long-term environmental harm is called sustainable development.Cause no harm and use least amount of energy as possibleWind farms, solar energy, hybrid cars, etc.
10 Natural resources: vital to human survival Natural resources = substances and energy sources needed for survivalRenewable resources:Perpetually available: sunlight, wind, wave energyRenew themselves over short periods: timber, water, soilThese can be destroyedNonrenewable resources: can be depletedOil, coal, minerals
12 Soil Erosion Soil erosion is the removal of soil by water or wind. Ex: dust bowl of the 1930s
13 How can farmers prevent soil erosion? Crop RotationLeaving stems/roots of previous plantAlter shape of land
14 Soil ErosionFarming, overgrazing, seasonal drought, and climate change can turn farmland into desert -desertification.Roughly 40 percent of Earth’s land is considered at risk for desertification.
15 Soil ErosionDeforestation, or the loss of forests. Half of the world’s old-growth forests have been lost to deforestation.Healthy forests hold soil in place,, absorb carbon dioxide, and help moderate local climate.Succession may occur after cutting
16 Water PollutionA pollutant is a harmful material that can enter the biosphere.Only 3 percent of Earth’s water is fresh water—most of that is locked in ice at the poles.Used for drinking water, industry, transportation, energy, and waste disposal
17 Biological magnification Increase in concentration of a certain substance throughout a food chain. Ex: Mercury
18 What are some forms of air pollution? SmogAcid RainGreenhouse gasesParticulates
19 SmogSmog is a gray-brown haze formed by chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.