Unit 2: Global Climate Change

Specific Heat Formula

energy flow = mass x specific heat x temperature change

\
specific heat = energy flow/(mass x change in temp)

Milankovitch Cycles

Eccentricity, Axial Tilt, Precession

Eccentricity

The shape of Earth's orbit around the Sun - reduces/increases amount of radiation

Aphelion

Earth's farthest point from the sun

Perihelion

Earth's closest point to the Sun

Current Milankovitch Cycles

Least elliptic (most circular), Medium tilt, Pointing at north star

Axial Tilt

The inclination of the Earth's axis in relation to its plane of orbit around the Sun - Seasons

Precession

The Earth's slow wobble as it spins on its axis - seasonal contrasts

Insolation

Incoming Solar Radiation - Energy from the Sun that interacts with our atmosphere, hydrosphere, and lithosphere - mostly in the form of visible light

Factors affecting how much sunlight reaches a given area

1. Sun Angle

2. Air Mass

3. Day Length

4. Cloud Coverage

5. Pollution Levels

Insolation (measure)

A measure of the solar energy striking a specified area over a set period of time

Factors affecting insolation

1. The angle of insolation

2. The duration of insolation

3. The nature of Earth's surface

4. Change of phase and photosynthesis

Latitude

At the equator (0 degrees) the sun hits directly and at the poles it comes in at an angle.

External Forcings

Changes in the amount of solar radiation and changes in the characteristics of the atmosphere

Four Major External Forcings

1. Milankovitch Cycles

2. Variations in solar energy sunspots

3. Changes in Atmospheric Albedo

4. Carbon Cycle

Sunspots

Huge magnetic storms on the Sun's surface which release increased solar radiation to Earth

Albedo Effect

The reflection of insolation

Albedo Effect Causes

Volcanoes, wildfires (ash & soot reflect)

Higher Albedo impacts

Less insolation reaching Earth
Lower temperature
Current infrared trapped in atmosphere?

Long Term Carbon Cycle

1. Carbon Dioxide released (volcano)

2. CO2 stays in atmosphere until washed out of atmosphere by rain (forms Carbonic Acid)

3. Acid rain dissolves rocks forming calcium carbonate in solution

4. Calcium Carbonate goes into rivers and then the sea

5. Calcium Carbonate removed from water by coral and other sea organisms

6. Coral dies and falls to the sea bed (forms Limestone)

7. Limestone moved to a destructive plate boundary and pushed into a subduction zone

8. Carbon Dioxide released (volcano)

Short Term Carbon Cycle

1. Producers store carbon from atmosphere through photosynthesis

2. Plants die and decompose, releasing carbon into the atmosphere

3. Consumers break down carbon molecules

4. Consumers release water vapor and CO2 into atmosphere as waste products through respiration

Plants produce the oxygen consumers breathe in

Atmosphere + Insolation

Infrared is absorbed by Carbon Dioxide, Methane, and Water Vapor (warms atmosphere)

Greenhouse Effect

Atmosphere allows sunlight to reach Earth's surface but prevents the heat from escaping back into space

Keeps our planet warm (we survive) - INCREASE is the issue

The surface absorbs shortwave insolation and reradiates infrared!

Greenhouse Effect Causes

1. Raising more cattle (methane)

2. Increased combustion of fossil fuels (carbon dioxide and water vapor)

3. Other gases

Global Warming

An increase in Earth's temperature due to an increase in greenhouse gases

Global Warming Causes (Manmade)

1. Combustion of fossil fuels (CO2)

2. Livestock Production (Methane)

Global Warming Effects

Ice caps/glaciers melting
Sea levels rise (melting and thermal expansion)
More severe storms
Change in climate patterns
Deforestation
Increased wildfires
Increase in # and strength of hurricanes (warmer water)
Ocean Acidification (taking in CO2 changes ocean ph which affects ocean wildlife)

Global Warming Causes (Natural)

1. Sunspots

2. Milankovitch Cycles

3. Volcanic Activity