Key Concepts
How is climate different from weather?
What factors determine the climate of a region?
How do scientists study past climates?
What natural forces contribute to climate change?
How are human activities affecting Earth's climate?
Vocabulary
climate
desert
ice ages
El Niño
global warming
Reading Strategy
Building Vocabulary Copy the partially completed concept map below. Then, as you read, complete it with terms from this section.
Figure 31 This postcard shows a warm coastal climate. Classifying How might a postcard for your town illustrate its climate?
A friend from another state wants to visit you during school vacation. She's never been to your area, and wants to know what type of clothes to bring. Should she bring her heavy coat or her rain gear? How would you answer her? You could look outside to check the current weather, but that can change quickly. What your friend really needs to know is the typical weather for your area at that time of year. She needs to know about the climate, which is the long-term weather conditions of a place or region. Climate is a description of the pattern of weather over many years. It includes average weather conditions as well as how weather varies over time, rather than day-to-day changes in the condition of the atmosphere.
Scientists divide the world's climates into several different types. What is the climate like in your part of the world? To find out, look at the world map in Figure 32. The map is divided into six major climate groups: tropical, temperate marine, temperate continental, polar, dry, and highlands. One of the six major groups, the dry climates, is determined mainly by precipitation. Another group, the highland climates, is determined mainly by elevation. The four remaining groups are determined mostly on the basis of temperature. Scientists further divide the major climate groups into many different specific climates. It is important to realize, however, that this map is not static. It changes with changing global temperatures and patterns of precipitation.