Transcript Climate Change

Climate Change
Factors that Affect Climate
• Atmosphere
– The atmosphere of Earth is a layer of gases surrounding
the planet Earth that is retained by Earth's gravity
• Weather
– the state of the atmosphere as measured on a scale of hot
or cold, wet or dry, calm or stormy, clear or cloudy. Day-today temperature and precipitation activity
• Climate
– the average atmospheric conditions over longer periods of
time. Sometimes referred to as the weather of the world.
• Is climate change a new phenomena?
– No, the earth’s climate conditions have changed over many
years, as seen in soil samples and fossil records, however
the human effect has added an amplification to the change
of the climate.
Earth and Sun
• Solar Cycle:
– Approx. every 11 years there is a change in
solar radiation by about 0.1 %
– Effect of climate: when the sun is stronger
there is warmer climate trends
• Movement of Earth in Space:
– Involves tilt and wobble and creates
seasons
• Eccentricity:
– Milankovitch Theory Every 100,000 years earth’s
orbit fluctuates from circular to cylindrical
– Effect the intensity of the seasons.
• Axial Tilt: the earth spins on an axis of 23.5˚
this causes the 4 seasons
Eccentricity
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• Wobble:the earth wobbles every 433
days by about 20 feet at the poles.
Minimum effect on climate although
blamed for climate change. It is caused
by ocean bottom pressures and
atmospheric pressures.
• Latitude:
– the closer to the poles the less direct solar
radiation there is. The sun’s rays hit an an
angle
– Effect the temperature
Atmosphere and Climate
• Gases in the atmosphere
–
–
–
–
Nitrogen Gas N2 (78%)
Oxygen Gas O2 (21%)
Argon Gas (0.9 %)
Carbon Dioxide Gas CO2 (0.03%)
Winds
• Winds and energy dispersion
– The winds are created by differences in air
temperature and they carry warm air to areas
north and south of the equator
• Winds and Ocean Currents
– Winds at the surface of the ocean effect or push
the water creating directions of ocean currents.
• Winds and precipitation
– The winds can carry moisture great distances from
bodies of water allowing for tropical weather. It can
also provide only dry air masses causing deserts.
Winds Cont’d
• Jet Streams:
– Fast flowing,
narrow air
currents found in
the tropopause of
the atmosphere.
The major jet
streams on Earth
are westerly
winds (flowing
west to east)
Hydrosphere and Climate
• Hydrosphere:
– describes the combined mass of water found on, under, and
over the surface of the planet.
• Heat Capacity: defined as the heat required to raise
unit mass of substance by one degree of temperature
• Oceans and Lakes act as heat reservoirs
– They hold onto the heat longer and keep moderate
temperatures in comparison to the atmosphere above them.
Water has a high heat capacity.
• Albedo: a surfaces reflectivity of sun’s radiation.
• Ice and snow reflect heat so help to cool the temperature of the
Earth
• Soil, trees and oceans have low albedo and absorb more heat
helping to raise global temperatures.
• Page 272 1-4, page 278 1-3 Unit 3, Chapter 7
Moving Continents and
Climate
Tectonic plates:
move about 3 cm a year changing the shape of
landmasses on earth. Effect ocean currents and heat
distribution and also lead to more volcanic eruptions
• Volcanic eruptions:
– Release gases and particles that block out
some radiation resulting in cooling of the
atmosphere
Human Activity and Climate
• Anthropogenic:
– Caused or produced by humans
• Human technology and the atmosphere:
– The industrial revolution has increase the amount
of CO2 in the atmosphere along with other
pollutants leading to global warming increases
– Humans have also impacted the ozone layer by
weakening it with CFC’s. This issues has started
to repair itself now that CFC are banned.