IB ESS HL 6.3 Climate Mitigation and Adaptation Question Bank

Pros - reduce carbon emissions [2max]
a. decrease in use of coal with high emissions will tend to reduce carbon emissions / switch (from coal with high emissions) to coal with low sulfur emissions reduces overall carbon emissions;
b. decrease in overall use of coal (both low sulfur content and high emissions coal) will decrease carbon emissions / there is a slight decrease in carbon-producing sources;
c. increase in renewables/nuclear/wind/solar will tend to reduce carbon emissions;

Cons - increase carbon emissions [2max]
d. overall increase in energy supply will tend to increase carbon emissions due to construction/maintenance/extraction / production of batteries for renewable energies requires extraction of materials which produces carbon emissions;
e. use of coal with low sulfur content will still produce carbon emissions;
f. overall proportion of carbon producing sources remains fairly constant;

Note: For credit for either pros or cons, link must be made to carbon/carbon dioxide emissions.
For pros, do not accept only 'use of low sulfur coal will reduce emissions'.
Conclusion [1max] needs to be balanced considering both sides of the argument for credit and makes a clear value judgement e.g.: Although there is a planned increase in the use of renewable energies (associated with low carbon emissions) the majority of energy will still be generated using coal that releases carbon dioxide; Conclusion is not mandatory, and 3 marks can be achieved through consideration of both pros and cons

Is effective [4 max]
a. California is the top producer of renewable energy in the USA, reducing GHG emissions / large proportion (54\%) of electricity comes from renewable sources which reduces GHG emissions / move to 100\% renewable electricity sources reduces future GHG emissions;
b. California has reduced use of coal to less than 1\% (by increasing use of renewable energy) which reduces CO2/GHG emissions;
c. by 2035 all new sales of cars will be 100 % carbon-free, reducing GHG emissions;
d. cutting power to homes during strong winds/burying power lines/campaigns will reduce risk of wildfires, which reduces release of $\mathrm{CO}_{2}$ /protects carbon sinks;
e. new development must consider fire risk hazards in impact assessments;
f. large number of Californians are vegetarian, which reduces meat consumption and therefore reduces release of methane ;
g. protecting giant sequoia trees/wetlands helps to protect carbon sink/absorb $\mathrm{CO}_{2}$;
h. reduce use of water (per person) reduces the energy/electricity needed for water pumps/distribution and may lower $\mathrm{CO}_{2}$ /GHG emissions;

Is not effective [4 max]:
i. change in government may change policies in the future;
j. 40 % of electricity is still produced by natural gas, which is a fossil fuel and therefore emits GHG when burnt;
k. cannot produce enough electricity to meet demand, as need to import energy from Mexico and out of state (don't know how that energy is produced);
I. people will still be able to purchase cars from neighbouring states and drive them in California / citizens will still be able to drive older carbon-fueled vehicles;
m. power cuts during high fire hazard periods mean electric cars cannot be charged, so this is not an effective solution; n. population is growing, suggesting more cars on the road in future/residential GHG production will increase;
o. wildfires are increasing, which will add $\mathrm{CO}_{2}$ to the atmosphere;
p. wildfires will reduce carbon sinks / wildfires reduce number of trees and therefore the absorption of $\mathrm{CO}_{2}$;
q. agricultural output is a major cause of GHG, and California is a major producer of food / transportation of farm produce (e.g. almonds/meat) produces $\mathrm{CO}_{2} / \mathrm{GHGs}$;
r. water transfers/pumping require high levels of energy, which will increase energy demand in the future due to increased drought conditions (which may involve burning fossil fuels);

Conclusion [1 max]: requires a balanced argument and a clear value judgement, such as, "While California's move to renewable electricity generation will greatly reduce the combustion of fossil fuels, the large number of forest fires will reduce its ability to mitigate climate change".

Marking guidance:

Accept other reasonable responses supported by the information in the resource booklet.
Note: Do not accept conclusions which do not refer to California's actions, such as, "California cannot stop climate change."

a. Change the variety of crops grown which are more suited to new weather conditions/select more resilient crops/cultivars/shift towards salt-tolerant or drought-tolerant crops;
b. Breed livestock that are more suitable for changing climate;
c. Diversify agriculture to reduce risk of losing all crops during one season / use of agroforestry to reduce impact of extreme weather on crops/cattle;
d. Increase water resources to cover dry periods;
e. Improve land drainage to avoid risk of floods;
f. Implement precision agriculture (e.g. GPS-guided irrigation, soil sensors, drip irrigation) to optimise water use;
g. Use regenerative farming practices (e.g. cover crops, reduced tillage, crop rotation, organic fertilisers) to improve soil health/carbon storage/resilience to extreme weather;
h. Develop more effective pesticides to address new (tropical) pest species;
i. Shift to indoor farming, where growing conditions (e.g. temperature, water availability) can be controlled/kept stable;