September 15, 2011

 Our species has been around about 60,000 years ◦ % of Earth’s 4.6 billion year history  Until about 12,000 years ago, we were hunter-gatherers  Since then, 3 major cultural changes have occurred ◦ Agricultural Revolution ◦ Industrial Revolution ◦ Information/Globalization Revolution

 These three revolutions have… ◦ Given us more energy and new technologies to alter/control more of the planet to meet our basic needs/wants ◦ Allowed expansion of human population, largely due to increased food supplies ◦ Increased environmental impact because of increased resource use, pollution, environmental degradation

 Survived by collecting edible wild plant parts, hunting, fishing, scavenging meat  Lived in small bands (fewer than 50) ◦ Worked together to get enough food to survive ◦ Populations grew slowly due to high infant mortality rates and average life span of 30-40

 Mostly little environmental impacts  More advanced hunter-gatherers… ◦ Used advanced fuels and fire to convert forests in to cultivated ◦ Contributed to extinction of some larger animals ◦ Altered the distribution of plants as they carried seeds/plants to new areas

 Exploited environment to survive  Environmental impact small and local… ◦ Small population sizes ◦ Low resource use per person ◦ Migration (allowed natural processes to repair damage they caused) ◦ Lack of technology

 Began years ago  Move from nomadic hunting-gathering to settled agricultural communities ◦ Learned how to domesticate wild animals ◦ Learned how to grow various wild food plants

 Practiced SLASH-AND-BURN CULTIVATION ◦ Clear small patches of forests by cutting down trees/vegetation ◦ Burn the underbrush ◦ Ashes help fertilize the often nutrient-poor soils  Used SHIFTING CULTIVATION ◦ After you use a patch for several years, soil becomes depleted of nutrients ◦ Clear another plot of land and plant it ◦ Abandon previous patch for years until soil becomes fertile again ◦ First form of sustainable cultivation

 Early farmers had fairly little impact on environment because… ◦ Dependence mostly on human muscle power and crude tools ◦ Population size/density were low ◦ Enough land was available so they could practice shifting cultivation

 CONSEQUENCES ◦ Using domesticated animals increased ability to expand agriculture and support more people ◦ Degraded/destroyed habitats of wild plants/animals  Cut down vast forests to supply wood for fuel/building material  Plowed large expanses of grassland  Built irrigation systems  Soil erosion, salt buildup in irrigated soils  Overgrazing encouraged desertification  Topsoil erosion

 CONSEQUENCES ( cont. ) ◦ Increased production/use/accumulation material goods  Growing volumes of waste and pollution ◦ Farmers could grow more than enough food for families ◦ Urbanization (formation of villages, towns, cities)  Concentrated sewage/wastes, polluted air and water, increased spread of disease ◦ Increased conflict over land ownership and water rights ◦ Survival of plants and animals (once critical to humanity) became less important

 Began in England in mid 1700s and spread to U.S. in 1800s  Rapid expansion of production, trade and distribution of material goods  Shift… ◦ From dependence on wood and flowing water ◦ To dependence on machines running on nonrenewable fossil fuels (coal and then oil and natural gas)  Led to switch from small-scale, localized production of handmade goods to large-scale production of machine-made goods  Fossil fuel-powered farm machinery, commercial fertilizers and new plant-breeding techniques increased crop yields

 New technologies give us increasingly rapid access to much more information on a global scale ◦ Scientific knowledge doubles about every 12 years and general information doubles about every 2.5 years  Positives ◦ Help us understand more about Earth ◦ Allow us to respond to environmental problems more effectively/rapidly ◦ Satellites allow surveying of resources, monitoring of changes on Earth ◦ Use computers to model and map environmental systems ◦ Reduce pollution/degradation by substituting data for materials/energy and communication for transport

 Negatives ◦ Provide overload of info ◦ Cause confusion, distraction, sense of hopelessness as we try to identify useful environmental information ◦ Increase environmental degradation and decrease cultural diversity as globalized economy spreads over most of Earth and homogenizes world’s cultures

 Download the article from Class Jump  Read the article keeping track of major significant effects (i.e. societal) and environmental impacts.  Write a reflection of these points, what the author is trying to convey, and your opinion of the article.  Typed, 1-2 page  Due next block