Biology
Chapter 4
4.1 The Role of Climate
I. What is climate?
Weather
The day-to-day condition of
Earth’s atmosphere at a particular
time and place
Climate
Average, year-after-year
conditions of temperature and
precipitation in a particular region
II. The Greenhouse Effect
Gases trap the heat energy of
sunlight inside Earth’s
atmosphere. Natural situation in
which heat is retained by this
layer of greenhouse gases.
***Carbon dioxide, methane,
water vapor, and a few other
atmospheric gases trap heat
energy and maintain Earth’s
temperature range
III. Effect of Latitude on Climate
The difference in heat distribution
with latitude has important
effects on Earth’s climate zones.
Earth has three main climate
zones:
a. Polar
b. Temperature
c. Tropical
Polar Zones
Cold areas where the sun’s rays
strike Earth at a very low angle.
a. Located – North / South Poles
b. Latitudes – 66.5 degrees  90
degrees North / South
Temperature Zones
a. Locate – Polar Zones and
Tropics
1. Affected by changing angle
of the sun over the course
of a year
2. Climate – hot – cold
depending on season
Tropical Zones (Tropics)
Direct or nearly direct sunlight
year-round
a. Located – near Equator
b.Latitude – 23.5 degrees North
23.5 degrees South
IV. Heat Transport in the Biosphere
Winds
Unequaling heating of Earth’s
surface drives winds and ocean
currents
Warm air tends to rise and cool
air tends to sink
a. Air that is heated over the
equator rises
b. Cooler air over the poles sinks
toward the ground
Ocean Currents
Upwelling
a. Cold water near the poles sinks
b.Flows parallel to the ocean
bottom
c. Rising again in warmer regions
Landmasses
a. Air mass cools
b.moisture condenses forming
clouds
c. Brings precipitation to
mountains
Rain Shadow
An area with a dry climate on the
far side of the mountain