Describing Climates
Climate can be discussed in a number of ways. For example, the United States is divided into nine climate regions. When discussing global climate, climatologists refer to three major climate zones: polar or cold, temperate or medium, and tropical or hot. How were these three zones determined?

A large collection of cumulative Opens in modal popup window weather data, some over 100 years old, helped divide up the United States into regions and Earth into climate zones.

climatologist who studies long-term weather patterns summarizes the data and calculates averages to describe the climate of a location.

cumulative
"The detective said it was not just one thing that made the person look guilty; it was the cumulative evidence."

climatologist
"a scientist who studies long-term weather patterns"

Given that there's no clear demarcation between weather and climate, and the weather changes frequently, how is it possible to know that the climate isn't changing?”

Scientists do use clear demarcations between weather an climate. One example being the standard climatological period, which is 30 years. While it is true that some climatologists will study climate phenomena on different time scales; there are standard demarcations used to differentiate weather and climate.

The Earth’s climate is in fact changing, and this is revealed through measurements and archives of climate conditions that span great lengths of time

Explanation: