E3: Greenhouse Gas Effects (UNMODIFIED)

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Natural Greenhouse Gases: CO2, H2O Vapor, CH4

Temperatures at Sea Level:

With GHG: 16˚C

Without GHG: -18˚C

Process of Greenhouse Gas:

Solar Radiation (Short visible wavelengths and UV light) passes through atmosphere

Some solar radiation = reflected off clouds surface back into space

Some solar radiation = absorbed by Earth's surface + warms it

Energy radiated to Earth's Surface = Radiated back into atmosphere (as IR aka "heat")

Some IR = passed through space

Greenhouse gases in atmosphere absorbs IR Radiation, and then re-radiates back to Earth (therefore further heating Earth)

Process Name: GREENHOUSE EFFECT

Introduction:

Human activity = increased greenhouse gas in the atmosphere (dramatically since human industrialization era)

Greenhouse effects still active, but increase in re-radiation, therefore increasing global temperatures (global warming)

What is Greenhouse Gas?

A gaseous particle that has the ability to absorb and re-radiate IR Radiation

Main types: CO2, CH4, CFCs, O3, N2O

TO NOTE: H2O is not included in "enhanced GHG list" (Since it is naturally present in the atmosphere, and not anthropologically caused)

Sources:

H2O (Water from lakes and ocean)

CO2 (Combustion of fossil fuels, decomposition of organic matter, forest fires)

CH4 (Anaerobic Decomposition (e.g. in swamps), Intensive agriculture (e.g. rice paddies), oil and gas fields)

CFCs (Refrigerants, Solvents, Foaming Agents)

O3 (Photochemical Smog)

N2O (Use of Artificial Fertilizer)

Contributions of Greenhouse Effect depends on...

Ability to absorb IR

Greenhouse Factor:|| The ability of any particle to absorb IR radiation.||

Value = compared to CO2

Greenhouse Factor Values:

CO2 = 1

H2O (0.1)

e.g. "CFCs are 20 0000x more effective than CO2 to absorb IR Radiation"

Relative Abundance in Atmosphere

CO2 = more detrimental than CFCs (despite the greenhouse factor values) since it is the most abundant greenhouse gas in the atmosphere

Atmosphere

CO2 and CH4 Levels

Levels of CH4 and (esp.) CO2 have risen over the last 50 years

Increase of CO2 by 70ppm annually

Annual cycle = drop of CO2 during April - September, then peak of CO2 from October - March (due to plant growth in the Northern Hemisphere. Most likely vice versa for Southern Hemisphere)

Global Warming proportional to Global increase in CO2 (as seen through long term measurement of atmospheric CO2 and temperature anomalies)

Warming

Range of global warming = 1˚C - 4˚C (low CO2 growth VS high CO2 growth)

Despite small values, serious and deleterious consequences on other factors of the ecosystem

Habitat

Species will most likely redistribution / go extinct due to temperature deviations

Reason:

Desertification due to droughts

Warming of Cold Terrestrials/ Water Temperature

Loss of Ice

Agriculture

Agriculture

Agriculture

Agriculture

Crop yields will change (therefore, crop distribution will change as well)

Reason:

Will decrease due to desertification

Move to the northern regions (due to longer growing seasons)

Sea

Sea Levels:

Predicted to rise

Reason:

Thermal expansion of water (due to increased temperature)

Melting polar ice caps

Melting of glaciers

Outcome:

Coastal Communities = at risk (due to intensified flooding)

Large scale relocation of human population

Human Health

Expected to increase for certain types of diseases (e.g. malaria)

Reason:

Warmer temperature will increase geographical location of mosquitos

Life cycle of disease will change (and most likely extended season)

Natural GGE

Enhanced GGE Introduction

Effects of GHE

Influences of GHE