<p> Why study environmental science?</p><p>Environmental science is the study of how humans impact the environment.</p><p>Major Issues in Environmental Science  Population Growth: as the number of people increases more demands are placed on the environment  Pollution: an undesired change in air, water, or soil  Biodiversity: the variety of species in an area  Ecological Footprint: the area of Earth needed to support one person in a particular country  Sustainability: using resources at a slow enough rate so that they can be replaced</p><p>Changes in the Environment Through Time 1. Hunter-gatherers a. obtain food by hunting & eating plants b. small populations c. nomadic- they followed the food d. affected environment by overhunting Ex: hunted saber-toothed tigers to extinction</p><p>2. Agricultural Revolution a. planted seeds from plants & domesticated animals b. allowed human populations to grow because they did not have to move from place to place c. settled in small towns d. affected environment by destroying forest habitats to plant crops & build towns, depleted the soil of nutrients</p><p>3. Industrial Revolution a. mid 1700s fossil fuels began to power farm equipment & other machines b. food became cheaper & populations grew rapidly c. more people moved to urban areas because less people were needed for farming. d. affected environment by adding more pollution to air & water, producing materials that do not break down like plastic Why study environmental science?</p><p>______is the ______of how ______the environment.</p><p>Major ______in ______science • ______: as the number of people ______more ______are placed on the ______• ______: an ______change in _____, ______, or ______• ______: the ______of ______in an ______• ______: the ______of ______needed to ______one ______in a particular ______• ______: using ______at a slow enough ______so that they can be ______</p><p>Why study environmental science?</p><p>______is the ______of how ______the environment.</p><p>Major ______in ______science • ______: as the number of people ______more ______are placed on the ______• ______: an ______change in _____, ______, or ______• ______: the ______of ______in an ______• ______: the ______of ______needed to ______one ______in a particular ______• ______: using ______at a slow enough ______so that they can be ______in the ______Through ______1. ______a. obtain food by ______& ______b. ______c. ______- they ______the food d. ______environment by ______Ex: hunted ______to ______</p><p>2. ______a. ______from plants & ______animals b. allowed human populations to ______because they ______to place c. settled in ______d. affected environment by ______to plant ______& ______, ______the soil of ______</p><p>3. ______a. mid 1700s ______began to ______farm equipment & ______b. ______became ______& ______grew ______c. more ______moved to ______because ______people were needed for ______. d. ______environment by ______more ______to _____ & ______, producing ______that ______like ______</p>