1.
2.
3.
What are nitrogen fixers, and why are they
important?
__________ break dead organisms down into
matter. This adds carbon and nitrogen back
into the ecosystem.
Giant panda bears have a very low birth
rate. Before they became a protected
species, they were frequently poached, and
lost much of their old habitats. Did they
have a positive or negative growth rate?
What determines our climate?

Climate refers to the average yearly
conditions of temperature and precipitation.
◦ Contrast with weather, the day-to-day conditions.


The biggest difference between climate and
weather?
Weather changes frequently each day, but
climate rarely changes from year to year.
Climate is determined by several factors.
1. How well heat is trapped by the
atmosphere.
2. The latitude (north-south position) of each
region.
3. The presence of wind and ocean currents.
4. The amount of precipitation present.


Our atmosphere contains trace amounts of
important greenhouse gases – gases that are
capable of trapping heat energy.
◦ Greenhouse gases include carbon dioxide, methane
and water vapor.

Greenhouse gases trap heat energy, which
keeps our atmosphere warm.
◦ Without them, Earth would be 30 degrees Celsius
cooler. That amounts to 86 degrees Fahrenheit!

However, too many greenhouse gases is not a
good thing, either!



Due to Earth’s shape and its tilted axis, the
Earth does NOT receive sunlight evenly.
Sunlight is the primary means of heating up
the atmosphere. Therefore, certain parts of
Earth get a lot of direct sunlight, and are
quite warm.
Other parts of Earth get little direct sunlight,
and are quite cold.



The polar zones are
at the very top and
bottom of Earth.
They get very little
direct sunlight; the
sun’s rays are at
very low angles.
These regions are
cold year-round.



The tropical zone is
located around the
equator.
This region gets
direct sunlight
almost all year
round.
As such, this region
is quite warm yearround.



The temperate zones
are located in
between the polar
and tropical zones.
The angle of sunlight
varies greatly during
the year.
As such, climate
changes from hot to
cold, based on the
seasons.




Throughout Earth, warm air and water rises,
and cool air and water sinks. This principle is
known as convection.
Convection causes air currents, better known
as wind.
Convection also causes many ocean currents.
Wind also produces ocean currents.
Currents transport heat all over Earth. Warm
currents keep climate moderate, and cool
currents make climate cold.

Areas close to large bodies of water are likely
to see a lot of precipitation.
◦ Why?



Mountain ranges create rain shadows.
Basically, clouds are forced upward due to the
mountain range, which cools them down.
This makes precipitation much more likely,
and the cloud disappears.
As a result, the other side of the mountain is
a lot less likely to get precipitation, creating a
dry climate behind the mountain range.
1.
2.
3.
4.
5.
What is the difference between climate and
weather?
___________ gases trap heat in the
atmosphere, which keeps Earth warm.
The [polar, temperate, tropical] zone(s) have
the largest range of possible climates.
The [polar, temperate, tropical] zone(s)
receive little direct sunlight.
True or false: In convection, cool air rises,
and warm air sinks.