Greenhouse effect

Question 1

What are the types of energy and where do they come from? And what are the exceptions

Answer 1

Vast majority comes from the sun directly or indirectly

Biomass from photosynthesis to convert sunlight into sugars

Wind is caused by the sun heating which causes movement of air

Wind causes waves as it passes over the oceans

Rain comes from solar evaporation which supplies hydroelectric power

Fossil fuels essentially comes from energy from the sun

Exceptions:
Nuclear- energy from radioactive decay

Geothermal- GPE, Accretion+Nuclear

Tidal Power- GPE

Question 2

What are the types of atmospheric scattering?

Answer 2

Rayleigh scattering- small particles compared to wavelength of light

Mie scattering- depends on shape of scatterer particle, about the same size as wavelength of light

Geometric scattering
particle much larger than wavelength of light

Question 3

What is the definition of absorbance (equation)?

Answer 3

A=-log10(I/Io) where, I is the thickness of media

Question 4

What is the greenhouse effect? (Exam question)

Answer 4

The overall result is that the atmosphere acts like the glass in a greenhouse – it lets the sunlight in but doesn’t let the radiated heat back out again. 
The sun emits UV, visible and IR radiation. The UV is largely absorbed/scattered by oxygen and ozone and Rayleigh scattering. Visible light passes through the atmosphere, and much of the IR is absorbed by water vapour, but there are some transmission windows in the IR. 
Greenhouse gases (GHGs) in the atmosphere absorb and re-emit infrared radiation, but they do not absorb the visible sunlight. Therefore they will allow the incoming light through but block that radiated from the Earth. This is because they close off part of the IR transmission windows.

Question 5

How does CO2,O2 and H2O contribute to the greenhouse effect? (EXAM QUESTION)

Answer 5

the sun emits radiation across the UV-IR parts of the electromagnetic spectrum. Water vapour is transparent to visible light but absorbs many bands within the IR part of the spectrum. However, there are some IR windows that remain transparent.
ii oxygen and ozone absorb strongly in the UV part of the spectrum. (1)
iii carbon dioxide absorbs IR radiation that would otherwise escape the planet within one of the IR window left open by the water vapour (1). This means less of the IR radiation re-emitted by the Earth (much cooler than the Sun) can escape and the planet warms as a result.

Question 6

What are the predicted consequences of Climate Change?

Answer 6

• Sea level rise
• Global temperature rise
• Warming oceans
• Glacial retreat
• Declining Arctic sea ice
• Shrinking land ice sheets
• Extreme events
• Ocean acidification
• Decreased snow cover

Question 7

Explain the carbon cycle? (8 steps)

Answer 7

1. Plants absorb C02 from air to grow, and decompose to release C02
2. Iron-rich dust is blown by winds into the ocean and stimulates phytoplankton blooms
3. Air and sea exchange CO2
4. Phytoplankton take up CO2 to grow
5. Zooplankton eat phytoplankton and respire CO2
6. Some carbon sinks to the bottom in the form of decaying biota and fecal pellets
7. Most carbon is recycled back to land after a period of time
8. Rocks are eventually uplifted to land and weathered to release carbon to soil and the atmosphere

Question 8

What time of CO2 sources are there?q

Answer 8

Stationary- power plants, ethanol plants, petroleum and gas processing facilities, cement and lime manufacturing plants, iron and steel production, fertilizer production
Mobile

Question 9

How do you assess CO2 sources?

Answer 9

Continuous emission monitoring
Emission factors
Emissions estimate equations

Question 10

How can we commit to carbon reduction?

Answer 10

Higher efficiency Conversion process ( more efficient use of fossil fuels)
Medium term CO2 capture and storage
Long term: Fuel switching to Low carbon alternatives

Question 11

What is direct radiation?

Answer 11

Light that doesn’t interact with the atmosphere

Question 12

What is indirect radiation

Answer 12

Light that has been scattered in the atmosphere

Question 13

What is scattering

Answer 13

Describes several processes like reflection and scattering that can alter the direction that light is travelling

Question 14

What is absorption

Answer 14

Energy as electromagnetic radiation is taken up by the molecules in the atmosphere. Energy is transferred to electrons with molecules resulting in the generation of heat

Question 15

What is emission

Answer 15

The amount and wavelength of the radiation emitted by an object, which depends on its temperature.