Download Long-Term and Short-Term Changes in Climate

Long-Term and Short-Term
Changes in Climate
•The Earth is 4.54 billion years
old
•In it’s history, there have been
many natural variations to it’s
climate
•These change have occurred due
to changes in how energy is
absorbed and trapped by the
Earth
For example…
• Ice Ages
▫ a period in Earth’s history where the
Earth is colder and much of the planet is
covered in ice
Long-Term Changes are due to:
Continental Drift
• According to plate tectonics, all of the
continents have been moving and are
continuing to shift their position on the
Earth’s surface
• How it impacts climate?
▫ Changes ocean currents and wind patterns
▫ Changes how land masses are distributed
which reduces the effect of local bodies of
water on climate
▫ Creates mountains which affect climate
Video
Cycles in Climate
• Long term cycles (over tens and hundreds
of thousands of years) occur alternating
between ice ages and warmer interglacial
periods
• Theories on why the climate changes:
▫ Shape of the orbit changes over time
▫ Earth’s tilt changes and wobbles
Short-Term Changes are caused by:
Volcanic Eruptions
• When an eruption occurs, rocks, dust and gas
are shot high into the atmosphere
• These particles reflect the suns rays and lower
the energy transmitted to the Earth
Changing Ocean Currents
• El Nino – a recurring change in the Pacific winds
and ocean currents that brings warm, moist air
and water toward South America instead of
Africa
Changes in the Sun’s Radiation
• If the amount of radiation from the Sun
drops, the Earth receives less energy and
cools
• Scientist’s are constantly monitoring the
Sun’s energy output
Homework
• Pg 353 # 2, 4, 5, 7