The number of times heads comes up when you toss a coin, number of students present in class, number of times a person has attended therapy sessions-these are all discrete variables. To help see the difference between continuous and discrete variables, imagine a really tall mountain with a trail leading up to the top.
Climate changes resulting from greenhouse gas increases could also significantly affect water supply and demand. For example, a local increase in temperature of several degrees Celsius could decrease runoff in the Colorado River Basin by tens of percent (25, 48).
In the industrial era, human activities have added greenhouse gases to the atmosphere, primarily through the burning of fossil fuels and clearing of forests. Adding more of a greenhouse gas, such as CO2, to the atmosphere intensifies the greenhouse effect, thus warming Earthâs climate.