It all begins with the sun……
Uneven Heating of the Earth
The Sun - The Earth's major source of energy
The Earth is constantly receiving solar energy, but
different areas of Earth receive different amounts of solar
energy.
This affects weather and climate.
Different areas of the Earth receive different amounts of
sunlight.
The equator receives the most sunlight because the
Sun is closer to being directly overhead year-round than
it is at any other place on the Earth.
This increases the amount of heat energy received and
explains why areas near the equator have tropical
climates.
 The poles receive the least sunlight, which is why they
have cold climates.
 The solar energy received by the Earth causes ocean
currents, winds, seasons, and climate differences.
OCEAN CURRENTS
The uneven heating of the Earth's surface creates
energy flow.
Winds and ocean currents flow from warmer areas to
colder areas, which means that they travel from the
equator toward the poles.
Because water has a much higher heat capacity (absorbs
and lets go of heat more) slowly than land, water temperature
will increase and decrease less than land temperature.
For example, during daytime, land temperatures might
change by tens of degrees, while water temperature change
by less than half a degree.
This means that coastal land temperatures don’t
fluctuate (go up and down) extremely (a lot) because the
ocean water nearby doesn’t fluctuate much.
•Upwelling
Causes cold, nutrient rich water from the deep ocean to
rise to the surface.
El Nino and La Nina
 El Nino is a change in water temperature in the
Pacific ocean that produces a warm current.
 La Nina is a change in temperature in the Eastern
Pacific that causes surface water temperature to be
much colder than usual
 BOTH El nino and La Nina can cause flooding (too
much rain) and drought (too little rain) in different
places on Earth. Upwelling does not occur where it
normally would and this affects fish and sealife.
Coriolis Effect
Because of the Coriolis Effect, winds appear to
deflected to the east or west depending on the direction
winds are traveling.
Uneven distribution
of sun’s energy
Current
movements
Deep water wave
Coriolis Effect
Relationship between Atlantic Thermohaline
Circulation and Global Warming
Result of Global Warming:
 Significant slowing of the ocean circulation that
transfers warm water to the North Atlantic Ocean
 The southern hemisphere would become warmer
and the northern hemisphere would become
colder
Why?
Higher temperatures under global warming
Increasing the precipitation, melting nearby sea ice,
mountain glaciers and the Greenland ice sheet
Add fresh water to the northern oceans
The influx of fresh water reduce the surface
salinity and density
Dense water then sinks and slowly travels through the deep
water southward into the Southern Hemisphere
Lead to the significant slowing of the thermohaline
circulation
The North Atlantic Sink
Impacts of ocean current slow down
 Distinct regional
variability
 Bitter winters as Little Ice
Age 17th-19th centuries
 possibly related to
changes in the strength of
North Atlantic
thermohaline circulation
 10,000 years ago, a period
called ‘Younger Dryas’
caused European
temperature dropped >10C
The Day After Tomorrow?
Solution
 The Framework Convention
on Climate Change
(UNFCCC) – Stabilizing Greenhouse
Gases (1994)
International Cooperation :
Kyoto Protocol (1997); USA rejected
Produce less green house gases,
e.g. CO2 , Methane
China`s responsibility
1. Regions at different latitudes around the world receive
different amounts of solar radiation. Polar regions receive the
least amount of solar radiation, while the equator receives the
most. How does this most likely affect the global climate?
A. polar regions experience colder climates
B. the global climate is mostly cold
C. the global climate is mostly warm
D. equatorial regions experience colder climates
2. Seasonal changes in water temperature tend to remain
within a narrow range. This is opposed to air temperature,
which tends to fluctuate across a wide range. The relative
stability of ocean temperatures helps to regulate the
temperatures of coastal regions. Why can water remain
within a narrow range of temperatures?
A. It has a high heat capacity.
B. It is mobile and this allows heated water to sink.
C. It reflects heat and does not absorb heat.
D. It is only stable within a small temperature range.
3. Convection currents, resulting from uneven heating
of the Earth's surface, cause _________ to form.
A. wind
B. mountains
C. volcanoes
D. fossils
4. Ocean currents and global wind patterns, which are
caused by convection currents, most strongly affect a
region's...
A. latitude.
B. population size.
C. day length.
D. climate.
5. Water is cooler near the poles and warmer near the
equator. Movement of cooler and warmer water from these
regions moderates the global climate.
Which of the following describes the movement of water
between the poles and the equator?
A. tides
B. ocean currents
C. evaporation
D. gravity
6. Which property of oceans best explains why they have
a major effect on climate?
A. They contain large amounts of dissolved salt.
B. They have a constant tidal movement.
C. They absorb gases from the atmosphere.
D. They hold a large amount of heat energy.
1. Regions at different latitudes around the world
receive different amounts of solar radiation.
Polar regions receive the least amount of solar
radiation, while the equator receives the most.
How does this most likely affect the global
climate?
Answer:
A. polar regions experience colder climates
2. Seasonal changes in water temperature tend to
remain within a narrow range. This is opposed to air
temperature, which tends to fluctuate across a wide
range. The relative stability of ocean temperatures helps
to regulate the temperatures of coastal regions. Why can
water remain within a narrow range of temperatures?
A. It has a high heat capacity.
3. Convection currents, resulting from uneven heating of
the Earth's surface, cause _________ to form.
A. wind
4. Ocean currents and global wind patterns, which are
caused by convection currents, most strongly affect a
region's...
Answer:
D. climate.
5. Water is cooler near the poles and warmer near the
equator. Movement of cooler and warmer water from
these regions moderates the global climate. Which of
the following describes the movement of water between
the poles and the equator?
Answer:
B. ocean currents
6. Which property of oceans best explains why they have
a major effect on climate?
Answer:
D. They hold a large amount of heat energy.