Week 10 Flashcards
MAR 27
Con’d
Demand-side mitigation
- back to Lancet bar graph
Plant-Rich Diet:
b/c…
Graph: Kg of consumed food by kg CO2 equivalent
— Lamb, beef and cheese biggest
Production emissions (on farm)
— Post farm gate emission (processing, cooking, transport, retail, waste disposal)
Everything has larger production emissions EXCEPT:
UNITS are important to remember… is kg a fair way to represent GHG emissions
But is it fair to compare GHG emissions on a kg basis?
Is a kg of meat = to a kg of broccoli?
NO
Kg of beef = 2,280 cal
Kg of broccoli = 340 calories
*** So If we achieve all of the above at 50% can reduce 506gt (63% reduction)
Could reach 1.5 degree limit
IF we did all - we could be in the -7Gt
: reduced meat, not vegan (48% reduction inclusive of the things above it as well)
b/c… Particularly ruminant meat consumption [can convert grasses to protein but it is a fermentation process - produces/releases methane]
EXCEPT: potatoes they have larger post farmgate - due to possibly potato chips mainly (processing requires a huge amount of energy)
Energy Conservation:
– Shifting behaviours:
→ MANY of these require political
– :
Walking/biking instead of driving
Etc listed above
–>:
will and governance such as:
Good city planning (walkable cities, bike paths, public transportation etc)
Incentives (ex: buying longer lasting appliance/ plant based options cheaper - subsidies)
Education
IPCC Report AR6 Synthesis Report
–> Potential of demand-side (behavioural) mitigation options by 2050 [pathway white bar comes from : all of the agreements countries have made to date]
→ Land transport - teleworking; walking, cycling, public transport; city planning, electric vehicles (67% decrease)
→ Buildings - lifestyle and beh changes; compact cities, reduced living space, urban planning, energy efficiency (66% decrease)
→ Industry - sustainable consumption (longer-lived products); networks for recycling, repurposing, reuse (29% decrease)
→ Food (44% decrease)
*** again to decrease faucet we need demand and supply side mitigation
Supply-side mitigation
–> Renewable energy
- Derived from:
- Importance of:
–
–>
Derived from: “natural” processes that are replenished constantly
* Solar, wind, hydroelectric, etc
– Importance of electrification
– Electric power can be more efficient and we can “clean
it up”
3 Types of Solar
1
2
3
Wind Power Generation through:
1
2
3
Hydroelectric Energy
- Dam
1 Solar Electric (Photovoltaics)
2 Solar Thermal (Hot Water)
3 Passive Solar (Solar Heat)
1 Wind Turbines
2 Tidal Turbines
3 Tidal Barrage - NB one shut down cause of fish mortality
- Dam
Water flowing from high to low levels “creates energy”
Biomass Energy:
such as…
3 Ways to release the energy to produce biopower:
1
2
3
How is biomass energy carbon neutral?
- b/c
: Energy from living things
… animal waste, crops and agri waste, forestry products, sewage, energy crops, food waste
1 Burning directly to produce heat or steam (electrovity) - must be dried first
2 Bacterial Decomposition (anaerobic digestion) - Anaerobic bacteria produce methane to form a renewable natural gas
3 Conversion to gas/liquid fuel
- Gasification - biomass exposed to high temperatures with very little oxygen to produce synthesis gas (syngas)
- Pyrolysis - biomass heated at a lower temperature in the complete absence of oxygen to produce a crude bio-oil
b/c it contributes to a cyclical process if done right
Geothermal Energy:
1
2
1 Geothermal Power Station - heat from the Earth’s core used to heat water –> steam - used to turn a turbine of a generator and produce electricity
2 Geothermal heat pump
- soil temperatures below ground are relatively constant aat around 12C - this provides heating in the winter and cooling in the summer - uses pipes filled with water to transport heat either to or away from house
Nuclear
it is…
- NEW small modular reactors…
… low carbon but not renewable
Produce heat by splitting uranium atoms (fission)
- heat converted to steam which drives turbines to produce electricity
- low GHG emissions (but fossil fuels are consumed during uranium mining)
MAR 29
Nuclear CON’D
Small modular reactors…
- Public support for energy sources:
ranked 1-6
…
can be placed in locations not suited for lg reactors
more affordable & scalable
potential for enhanced safety
more testing needed
1 Solar (97% support) 2 Wind 3 Hydroelectric 4 Natural gas
- the drop down to 5 Coal, is by almost 40%
6 Nuclear energy (38% support)
Alternative Energy Sources
Benefits:
-
-
-
-
-
-
-
B
- Reduced carbon emissions (and air pollution)
- Diversified economy
- Decentralized (avail in remote or poor areas)
C
- Cost/infrastructure
- Variable output (solar and wind)
- Potential environmental impacts (nuclear waste; hydropower dams)
- Conflict over land use (biomass, solar, wind)
- “Nimbyism = not in my backyard”
Current Energy Sources
Oil 33%
Coal 27%
Gas 24%
84.3% of global energy comes from fossil fuels
16% from low carbon sources (11% from renewables)
Nuclear 4.3%
Hydropower 6.4%
Wind 2.2%
Solar 1.1%
What are the safest and cleanest sources of energy?
?
Death rate from accidents and air pollution: coal, oil and gas are highest whereas hydro, wind, nuclear and solar are very small relative
Co-benefits associated with renewables!!!
So faucet is decreased through demand and supply side mitigation
So Drain is increased through Carbon Capture and Storage (CCS)
Biological CCS:
1
2
3
* also direct air capture CCS
- problem…
Non biological CCS =
1
2
3
(1) reforestation or (2) afforestation; (3) avoid deforestation
*CO2 sticks on filters through fans & drawn off then buried
Problem: CO2 sequestration may not outweigh the CO2 of material to build and energy to run
1 Separation,
2 Transport,
3 Storage
[1] liquid capture
[2] filter that captures CO2
Involve sending it somewhere [buried] (deep aquifer, coal bed, gas reservoirs)
Umbrella term for this is Geoengineering
CCS challenges:
–> Reforestation/Afforestation…
-
-
-
- More than 100,000 sq km of tropical forests have disappeared each year since 2013 SO Huge numbers of trees needed to put a dent in CO2 emissions
- Would clash with the needs for food and biofuel crops
- CAN’t BE THE ONLY THING we use
–> Non-biological CCS
- Tech is current prohibitively expensive and might take decades to operate
IPCC AR6 WGIII
–> Shows the options avail now in all sectors to mitigate net emissions by 2030
– Bigger the bar the more potential it has to mitigate // Also colour according to cost - blue = low cost / red = more cost
SO…
… Agri, Forestry and other land use: Carbon sequestration is small bar & dark red
TWO largest bars are wind and solar…. Mainly blue (cost effective) and longest in terms of ability to mitigate
– Others that are good to note:
Efficient appliances
– All beh like fuel efficient transportation (public transport and electric), dietary changes
Ocean Iron Fertilization (Geoengineering CCS) =
Solar Radiation Management =
What could possibly go wrong?…
-
-
-
-
=
- Iron eutrophication technically - to fuel phytoplankton to sequester more CO2
- Negative consequences: toxic algal blooms, deep water oxygen levels, ecosystem impacts
= Theoretical measures to slow global warming by reflecting more sunlight away from Earth
- Involves cooling (no decrease in Co2) decreasing the amount of solar radiation reaching the earths surface
RIGHT side of diagram: inexpensive: paint human structures white (buildings), lightening color of crop leaves
LEFT side: giant space mirrors, reflective aerosol particles, marine cloud whitening (ships to spray sea water towards clouds) & ships to generate sea foam to be more reflective
?…
- Stratospheric aerosols
Unknown impacts on climate (precipitation)
- Ozone depletion
If they “sink” into troposphere may seed clouds an lead to increased warming - Lessened availability of solar power
- Seen as a crutch to allow continued carbon emissions
- Continued ocean acidification (if not focusing on CO2 at all - which is an issue in itself)
Danger of rapid CC if systems fail
