CK12 Earth Science

Vocabulary conserve To keep things safe and ensure that they will always be around. export To send out to another country. impor ...

Introduction Imagine that someone offers you a $100 bill that you can use for whatever you want. That would be a pretty good dea ...

Figure 20.8: It takes energy to get energy. This is an oil platform used for drilling oil from deep underground. It took lots of ...

than one means there is an overall energy loss. Table20.2shows several energy sources commonly used for heating our homes and sc ...

Energy Efficiency The discussion above on net energy shows you that it takes energy to get energy and that some sources of energ ...

Figure 20.10: This pie chart shows how energy is used in the United States. ( 10 ) ...

Table 20.3: Where Energy is Used How We Can Use Less En- ergy How We Can Use Energy More Efficiently Transportation Ride a bike ...

Table 20.3: (continued) Where Energy is Used How We Can Use Less En- ergy How We Can Use Energy More Efficiently Commercial (bus ...

Vocabulary energy The ability to do work which we can get from a fuel. extraction The process of taking oil out of the Earth. fl ...

(7) http://commons.wikimedia.org/wiki/Image: Opec_Organization_of_the_Petroleum_Exporting_Countries_countries.png. GNU-FDL. (8) ...

Chapter 21 Human Actions and Earth’s Waters 21.1 Humans and the Water Supply Learning Objectives Learn how humans use water. Di ...

Currently, agricultural uses the most water. Considering different methods of irrigation and times of day to water crops can imp ...

redistributed for reuse. These are examples ofnon-consumptive water use.By recycling water, we ultimately reduce our overall wat ...

irrigation to produce more crops or to grow more profitable crops. In some cases, farmers can choose to grow crops that match th ...

Figure 21.4: Aquaculture: Workers at a fish farm harvest fish they will sell to stores. ( 24 ) ...

Some of the most productive aquaculture farming takes place in wetland areas along coast- lines. Rivers and streams carry nutrie ...

Figure 21.6: Domestic water use. ( 20 ) developed countries use far less water than people in the United States. Globally, house ...

irrigate the golf course in order to keep it nice and green! The amount of water that most recreational activities use is low: l ...

Figure 21.9: California rivers. ( 6 ) ...

Groundwater is also an important source of water in California. In a normal year about 40% of the state’s water supply comes fro ...