Climate Change Greenhouse Effect, Greenhouse Gases, and Earth’s Energy Budget.

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?