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Physical
Climate Patterns
Climate patterns are the long-term averages and swings of weather in a region, shaped by the energy Earth gains from the sun and loses to space.
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The idea
Climate is the long-term weather pattern in a region, typically averaged over 30 years. Weather is what happens on a single day, while climate describes what is typical for a place. Scientists measure it through temperature, humidity, air pressure, wind and precipitation. A place's climate depends on its latitude, its terrain, its altitude, how the land is used, and the water bodies and currents nearby.
Climate patterns are driven by energy. Nearly all of the climate system's energy comes from the sun, and Earth radiates energy back out to space. The balance between the energy coming in and the energy going out is called Earth's energy budget. When more energy arrives than leaves, the climate system warms, and when more leaves, it cools.
Climate also varies naturally. Some swings come from processes inside the climate system, such as the Pacific decadal oscillation in the ocean. Others come from outside forces, such as changes in the sun's output or volcanic eruptions. Scientists sort climates into types, most often with the Köppen climate classification, which is based mainly on temperature and precipitation. These patterns matter because changes in climate affect sea level, plant life and human societies.
Check yourself
Question 1 of 3
Over about how long is a region's weather typically averaged to describe its climate?
Composition
what it's made of
- Temperature — One of the two measures most often used to classify a climate.
- Precipitation — Rain and snow, which together with temperature form the usual basis for climate types.
- Energy budget — The balance between energy arriving from the sun and energy leaving to space.
- Internal variability — Natural shifts that start inside the climate system, such as ocean oscillations.
- External forcing — Causes from outside the climate system, such as changes in solar output and volcanism.
Connection
how it relates
Under Earth Systems
Change
how and why it evolves
- Past
- Before the 19th century, very few direct climate observations were recorded. Scientists therefore study past climates through clues such as lake sediments, ice cores, tree rings and coral.
- Now
- Since the Industrial Revolution, human activities have increasingly affected the climate. The term climate change is now commonly used for today's warming, often called global warming.
- Next
- As the climate warms, its zones are expected to shift. Many species are expected to move toward the poles or upward in elevation in response.