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).
The greenhouse effect causes some of this energy to be waylaid in the atmosphere, absorbed and released by greenhouse gases. Without the greenhouse effect, Earthâs temperature would be below freezing. It is, in part, a natural process.