climate change greenhouse effect, greenhouse gases, and earth’s energy budget
TRANSCRIPT
Climate Change
Greenhouse Effect, Greenhouse Gases, and Earth’s Energy Budget
Let’s Review Climate…
What is climate?
Climate is the average weather conditions in an area over a long
period of time.
Climate is different from weather…WHY?
What factors determine the
climate in the area ?
Climate is determined by many things including
latitude, wind patterns, oceanic currents and the local
geography of an area.
What is the most important factor in
determining climate?The most important factor
is distance from the equator.
Have you ever gotten into a car that has been sitting in the sun for a while with it’s windows closed? Why does this happen?
Let’s Review Solar Energy…
• WavesThe energy from the sun travels to Earth in what
form?
• The Electromagnetic Spectrum
What is the sun’s energy called?
• NoDoes all the energy from the sun reach the Earth’s
surface?
• some UV, visible, infra red, microwaves and radio waves
What parts of the Electromagnetic Spectrum do
reach the earth’s surface?
The Electromagnetic Spectrum
The Greenhouse Effect• CO2, H2O, CH4(methane) N2O (nitrous oxide) and even
CFC’s are GHG’s(greenhouse gases)• Certain gases in the atmosphere absorb OUTGOING
radiation from Earth. (Earth radiates energy back into space like a hot potato)
• Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder (about -5ºF)– All water would be solid, no life could exist
• Because they warm our world like a greenhouse, these gases are referred to as greenhouse gases
• We NEED the Greenhouse Effect to survive
Earth’s Energy Budget
• 30% of incoming solar radiation is reflected back into space – Some is reflected back in space by clouds and atmosphere, Some
is is reflected back in space from Earth’s surface
• Albedo is an object’s ability to reflect radiation– Lighter colored surfaces (snow, ice) REFLECT all colors, reflects
more radiation, higher albedo– Darker-colored surfaces (blacktop, forest) ABSORB more radiation,
lower albedo- GETS HOT
• Greenhouse gases absorb heat energy that would normally radiate back into outer space
• Increasing GHGs will absorb more radiation, thus average global temperatures will RISE as a result
So what are the greenhouse gases and where do they come from?
Water VaporEvaporation,
transpiration, and cellular respiration
water vapor alone produces
somewhere between about a
third and two-thirds of the
greenhouse effect.
Carbon DioxideBurning fossil
fuels, volcanoes,
deforestation, animal
respiration
MethaneAnimal waste,
biomass burning, fossil fuels, landfills, livestock, rice
paddies, sewage and
wetlands, fracking
Nitrous OxideBiomass burning,
volcanoes, deforestation,
burning of fossil fuels, microbial
activity on fertilizers in the
soil
Natural vs. Anthropogenic GHGs
Natural: water vapor, CO2, methane, nitrous oxide
Antropogenic gases are: carbon dioxide, methane, nitrous oxide, chlorinated gases
Anthropogenic = Man-made
What Are the Sources of Man-Generated Greenhouse Gases?
Charles Keeling
• Began measuring CO2 concentrations daily on Mauna Loa in Hawaii in 1958 through retirement.
• Results were obvious• Human activities ARE
increasing CO2 in the atmosphere
Describe the trend that you notice in the graph
The concentration of CO2 has steadily increased over the past 50 years
We obtain information about past CO2 levels from ice cores.
Feedback Loops• (+) feedback- actions work
towards INCREASING the origin event – gets amplified– Microphone screech– “Snowball” effect
• (-) feedback- actions work to CANCEL or NEGATE the origin event-gets diminished– Thermostat
Feedback Loops
FACT: Warmer global temperatures is melting Arctic Ice, exposing darker ocean water beneath.
1) How is this event changing Earth’s albedo?
2) How does this event make warming worse?
Arctic Feedbacks
Other Climate Feedback Loops
Other climate feedback loops
Greenhouse Activity
• Heat lamps, beakers, construction paper, thermometers
2 minutes of heating per test, record data• Test 1- inverted vs. upright beaker• Test 2- white vs. black construction paper (w/
inverted beaker)
Which test (1 or 2) tests albedo? Which tests GHE?