Mini Lectures 1-3 Lecture 1.

Lecture 1

  1. Workshop stream selection

  2. Assesments

  3. Paper structure

Lecture 2

Define Climate Change:

Super wicked problem:

Example:

“Climate change”

Wicked problems:

“Problems that can not really be solved”

Examples:

Child poverty

NZ housing market

Climate change

Difference between super wicked and wicked problems?

  • Time - Need to act now, the longer it takes the more difficult it is to minimise the problem.

  • Self interest - People that seek to end the problem, are also causing it.

  • No central authority management

  • Policies discount the future irrationally - Enjoying the now, at the expense of the future.

Greenhouse effect:

Effect that is responsible for earths climate being 30degrees warmer than it would be if we didn’t have an atmosphere. It is an natural phenomena.

  1. Solar radiation comes from the sun.

  2. Moves down to earths surface.

  3. Some energy hits earths surface, and is reflected back to space.

  4. Some energy gets absorbed by earth surface. Then reradiated (Terrestrial radiation)

  5. Terrestrial radiation gets caught up and absorbed by different molecules in the atmosphere. (Greenhouse gases)

Greenhouse gas concentrations:

  • The concentrations of greenhouse gases in the earths atmosphere has been increasing over the years.

  • This means that when more solar radiation hits earths surface, and remitted back as terrestrial radiation, and gets absorbed by earths atmosphere, which means more heat is retained, and the earths atmospheric temperature increases.

Direct impacts:

  • Global temperature increases - (Atmosphere, oceans, land)

  • Increase in acidity in water bodies (Oceans, lakes, rivers)

- Carbon dioxide is soluble in water, so with large amounts of co2 above these water bodies, it drives co2 into these water bodies creating carbonic acid. (Which causes an decrease in ph)

Indirect impacts:

  • Rising sea levels - As temperature increases, more ice melts (glaciers) increasing sea water to rise & Thermal expansion on water.

  • Changes in rainfall - Some regions become drier and others wetter

  • Biodiversity loss - Challenges for organism survival due not being able to adapt to climate changes (ph in water, too dry, too wet, loss of habitat etc).

  • Agriculture - Food production becomes less viable due to changes in environmental conditions for some regions. (drought)

  • Uninhabitable regions - Causes areas to be more susceptible to tragic weather events, forcing people to move areas.

Climate change mitigation and adaptation:

Mitigation:

Strategies to reduce green house gas emissions in the atmosphere

Adaptation:

Strategies to adjust to living under the current climate conditions and those expected in the future.

A global local problem:

Aotearoa has unique climate change challenges:

Hydro damns

Most of electricity is produced by renewable resources, but if we needed to up scale and rely on bigger amounts of electricity we would be limited, because if we were to include more hydro damns, it could effect lot of ecological areas and other impacts that’ll need to be considered.

Dairy farms

Most of CO2 emissions come from the agriculture sector, which means there needs to be more strategies to minimise CO2 emissions in this area specifically.

NZ Glaciers

Regional aspects need to be considered, as these glaciers melt faster than other glaciers.

Summary:

Lecture 3

Greenhouse gases:

Any gas that can absorb infrared radiation contributes to the greenhouse effect.

  1. Does it have the right energy levels to absorb infrared radiation

  2. How do electrons move in that molecule as the atoms vibrate

Composition of earths atmosphere:

O2 = 20.9%

CO2 = 0.04%

N2 =78%

Other = 0.04%

Concentration units:

(ppm) or (ppb)

Polyatomic (3 different atoms) gas molecule: CO2

  1. Assymetric stretch of co2 - Absorbs infrared light

  2. Symmetric stretch - Does not absorb infrared light

Difference between green house gases and non-green house gases:

Greenhouse gas:

  • More than 2 molecules

  • 2 molecules and they are different

Green house gases: Examples

  • CO2

  • N2O

  • H2O

  • CH4

Non-greenhouse gases: Examples

  • N2

  • O2

  • Ar

CO2:

  • 76% anthropogenic greenhouse gases

  • Caused by combustion of fuels, heat generation, land use changes, metal smelters, cement production.

Methane:

  • 16% of anthropogenic green house gas emissions

  • Agriculture (effluent/manure), fossil fuel production, house hold waste (landfills, wastewater).

Nitrous oxide:

  • 6% anthropogenic green house gas emissions

  • Agriculture, biomass burning, fossil fuel combustion, wastewater treatment.

Fluorinated gases:

  • 2% anthropogenic green house gas emmision

  • No natural sources, aerosols, refrigerants, electricity transmission, aluminium production.

Water:

  • Water vapour strongly absorbs infrared radiation, and rather drives earths temperature.

  • As temperature increases, evaporation will increase from all water bodies, causing more atmospheric water, which leads to more cloud cover, and if there is more cloud cover and depth in clouds, will cause more precipitation.

Global warming potential:

The Global warming potential of a molecule depends on:

  • Its ability to absord infared radiation

  • It’s lifetime in the atmosphere

  • Whether other molecules absorb the same infrared radiation

Summary