2025 IB DP Environmental Systems and Societies 模擬試題連答案詳解

Percentage increase is calculated as: \(\frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100\). Substituting the values: \(\frac{17.5 - 17.2}{17.2} \times 100 = \frac{0.3}{17.2} \times 100 \approx 1.744\%\). Rounded to two decimal places, this is 1.74%.

[1 mark] for correct substitution into the formula: \(\frac{17.5 - 17.2}{17.2} \times 100\) or equivalent. [0.8 mark] for the correct final percentage of 1.74% (accept 1.7% or 1.74%).

The expansion of shrimp aquaculture involves the clear-cutting of mangrove trees, which removes the physical structure of the habitat. This leads to: 1. Loss of nursery grounds for fish and crustaceans. 2. Loss of nesting sites for birds. 3. Habitat fragmentation, which isolates populations and reduces genetic diversity.

Award 1 mark for identifying habitat destruction or fragmentation (e.g., clear-cutting mangroves). Award 0.8 mark for linking this directly to biodiversity loss (e.g., loss of nesting sites, decline in species richness, or food web disruption).

1. Runoff containing nitrogen and phosphorus enters the water body. 2. This causes algal blooms. 3. The algae die and sink to the bottom. 4. Aerobic bacteria decompose the dead organic matter, consuming oxygen in the process and lowering dissolved oxygen levels, causing hypoxia.

Award 1 mark for describing the initial nutrient enrichment and algal bloom (eutrophication). Award 0.8 mark for explaining that the decomposition of dead algae by aerobic decomposers depletes dissolved oxygen.

Technocentric approaches emphasize technological control of nature, utilizing concrete dams, dykes, and pumping stations. Ecocentric approaches focus on working with nature, conserving natural floodplains, and utilizing sustainable, community-managed methods such as floating rice farming.

Award 1 mark for clearly identifying the technocentric view (technological control, e.g., dykes/dams). Award 0.8 mark for clearly contrasting it with the ecocentric view (nature-focused, e.g., restoring floodplains, community adaptation).

Total land loss = \(2100 - 1850 = 250\) thousand hectares. Time period = \(2020 - 1990 = 30\) years. Average annual rate of loss = \(\frac{250\text{ thousand hectares}}{30\text{ years}} \approx 8.33\text{ thousand hectares per year}\).

Award 1 mark for the correct numerical calculation: \((2100 - 1850) / 30 = 8.33\). Award 0.8 mark for the correct unit (thousand hectares per year, or thousand ha/yr).

As global temperatures rise, thermal expansion of the oceans and melting ice sheets lead to sea-level rise. This forces saltwater from the ocean to intrude further inland into the delta's estuaries and aquifers. Farmers then irrigate crops with brackish water, depositing salt into the topsoil.

Award 1 mark for identifying sea-level rise (due to thermal expansion/melting glaciers) or increased evaporation due to higher temperatures. Award 0.8 mark for linking this to saltwater intrusion into rivers/groundwater used for irrigation.

Detritus represents dead organic material (decomposers/producers base). Crabs consume this primary organic matter, acting as the primary consumer (second trophic level).

Award 1 mark for identifying the crab as a 'primary consumer'. Award 0.8 mark for correctly identifying it as the 'second trophic level' or explaining that it feeds directly on primary organic matter.

River sediment carries natural nutrients that replenish the delta's soils during seasonal floods. When dams block this sediment, the soils lose their natural fertility. Farmers must use more chemical fertilizers, which is unsustainable due to high costs, soil acidification, and water pollution risks.

Award 1 mark for explaining that trapping sediment deprives the delta of natural nutrients/soil replenishment. Award 0.8 mark for linking this to a sustainability issue (e.g., increased reliance on expensive synthetic fertilizers, soil degradation, or erosion of the delta itself).

Use the water balance equation: \(\Delta S = P + R - E - A\). Substituting the given values: \(\Delta S = 450 + 120 - 520 - 80 = 570 - 600 = -30\text{ mm/yr}\).

1 mark for correct working showing the calculation step: \(450 + 120 - 520 - 80\). 0.8 marks for correct final value with units and negative sign: \(-30\text{ mm/yr}\) (accept \(-30\) without units).

First, find the total number of individuals: \(N = 10 + 15 + 5 = 30\). Calculate \(N(N-1) = 30 \times 29 = 870\). Next, calculate \(\sum n(n-1)\) for all species: Species X: \(10 \times 9 = 90\); Species Y: \(15 \times 14 = 210\); Species Z: \(5 \times 4 = 20\). Sum of \(n(n-1) = 90 + 210 + 20 = 320\). Calculate \(D = 870 / 320 = 2.71875\), which rounds to 2.72.

1 mark for correctly calculating the components \(N(N-1) = 870\) and \(\sum n(n-1) = 320\). 0.8 marks for the final correct index value of 2.72 (accept 2.7).

Use the doubling time formula: \(DT = 70 / \text{NIR}\). Substituting the given NIR of 2.1: \(DT = 70 / 2.1 = 33.33\) years. Rounded to the nearest whole number, this is 33 years.

1 mark for showing correct working using the formula \(70 / \text{NIR}\). 0.8 marks for the correct final answer of 33 years (accept 33).

Percentage increase is calculated as: \((\text{Value}_{2020} - \text{Value}_{2010}) / \text{Value}_{2010} \times 100 = (16.8 - 12.0) / 12.0 \times 100 = 4.8 / 12.0 \times 100 = 40\%\).

1 mark for the correct step of calculating the absolute increase (4.8) divided by the initial value (12.0). 0.8 marks for the final correct value of 40% (accept 40).

On the USDA soil texture triangle, a composition of 40% sand, 40% silt, and 20% clay falls directly within the boundaries of the 'Loam' texture class.

1.8 marks for identifying 'Loam' (accept 'loamy soil'). No partial credit is awarded.

Identify renewable resources: Biomass (150 TJ) + Hydropower (80 TJ) + Solar (20 TJ) = 250 TJ. Calculate total energy supply: 150 + 80 + 20 + 250 = 500 TJ. Percentage of renewable energy: \(250 / 500 \times 100 = 50\%\).

1 mark for identifying and sum of renewable resources (250 TJ) and total energy (500 TJ). 0.8 marks for the correct calculation of 50% (accept 50).

The perspective that nature has inherent rights independent of human utility is ecocentrism. One characteristic of this perspective is that it integrates social, spiritual, and environmental aspects into a holistic view, prioritizes bio-rights, and advocates for minimal disturbance of natural processes.

0.8 marks for identifying 'Ecocentrism' or 'Ecocentric' (accept 'Deep Ecologist'). 1 mark for outlining a valid characteristic (e.g., believes in bio-rights / intrinsic value of nature, favors small-scale technology, advocates for self-sufficiency, or promotes holistic conservation).

Use the productivity formula: \(NPP = GPP - R\). Substituting the given values: \(NPP = 4500 - 2800 = 1700\text{ g m}^{-2}\text{ yr}^{-1}\).

1 mark for showing correct working (\(4500 - 2800\)). 0.8 marks for the correct final answer of \(1700\text{ g m}^{-2}\text{ yr}^{-1}\) (accept \(1700\) without units).

Species-based strategies focus on protecting individual species through methods like captive breeding, reintroduction programs, CITES, or flagship species campaigns. Strengths: High public appeal (flagship species) can raise significant funding; can prevent imminent extinction of highly threatened key species; preserves genetic diversity in gene banks. Weaknesses: High cost per species; does not address root causes of decline like habitat destruction; can ignore less attractive but ecologically vital species. Habitat-based strategies focus on preserving whole ecosystems through protected areas, national parks, or nature reserves. Strengths: Protects many species simultaneously, including undiscovered or non-charismatic ones; preserves ecological niches, food webs, and ecosystem services; addresses habitat loss directly. Weaknesses: Can be difficult to police and enforce ('paper parks'); can lead to conflicts with local communities or indigenous populations if excluded; vulnerable to external threats like climate change. Conclusion: A combination of both is most effective because habitat protection maintains the ecological framework, while species-based efforts can target key ecological engineers or critically endangered species that need immediate support.

Award up to 3 marks for evaluating species-based strategies (must include at least one strength and one weakness for full marks). Award up to 3 marks for evaluating habitat-based strategies (must include at least one strength and one weakness for full marks). Award 1 mark for an explicit concluding evaluation/synthesis that clearly relates both approaches. Points may include: - Species-based strengths (e.g., high public appeal/funding, targeted action for critically endangered species) and weaknesses (e.g., expensive, fails to address habitat loss, neglects non-charismatic species). - Habitat-based strengths (e.g., preserves entire ecosystems, protects multiple species, maintains food webs) and weaknesses (e.g., conflict with local people, difficult to manage/enforce, vulnerable to edge effects/external threats). Max 6 marks.

(a) The food product with the highest virtual water content is Beef (15,400 litres/kg).

(b) Step 1: Calculate total litres needed: \(250 \times 1,800 = 450,000\text{ litres}\).
Step 2: Convert litres to cubic meters: \(450,000 / 1,000 = 450\text{ }m^3\).

(c) Animal products (beef, pork, chicken) represent higher trophic levels compared to plant-based products (rice, wheat, potatoes) which are primary producers. Because energy transfer between trophic levels is inefficient (only about 10% of energy is passed on), it requires a large amount of plant biomass (pasture, grain feed) to produce a single unit of animal biomass. This feed production requires immense irrigation and water resources, resulting in a much larger cumulative virtual water footprint for livestock than for direct crop consumption.

(d) 1. Depletion of groundwater/aquifers: Over-extraction of water for export crops leads to falling water tables.
2. Ecosystem degradation: Diverting surface water for irrigation reduces stream flows, drying up local wetlands, harming aquatic biodiversity, and causing soil salinization.

(a) [1 mark] Award 1 mark for identifying "Beef".

(b) [2 marks max]
- Award 1 mark for calculating the total volume in litres: \(250 \times 1,800 = 450,000\text{ L}\).
- Award 1 mark for converting to cubic meters with correct units: \(450\text{ }m^3\).

(c) [3 marks max]
- Award 1 mark for stating that livestock products occupy higher trophic levels while crop products are primary producers.
- Award 1 mark for explaining ecological inefficiency / energy loss (the 10% rule) between trophic levels.
- Award 1 mark for linking this loss to the necessity of consuming large quantities of plant feed (which require water to grow) to sustain animals, multiplying the total water input.

(d) [2 marks max] Award 1 mark for each valid environmental impact up to a maximum of 2:
- Aquifer/groundwater depletion.
- Decline in river levels/loss of aquatic habitat.
- Soil salinization due to prolonged intensive irrigation.
- Loss of local water security/desertification.

(a) Island Delta has the highest species richness (92 species). This is due to its large size (150 \(km^2\)), which decreases extinction rates, and its close proximity to the mainland (40 km), which increases immigration rates.

(b) Island Beta has significantly higher species richness (45 species) than Island Alpha (12 species). Both islands are situated at a similar distance from the mainland (~480–500 km), meaning immigration rates are comparable. However, Island Beta has a much larger area (120 \(km^2\) vs 10 \(km^2\)). A larger area provides a wider variety of ecological niches and resources, allowing for larger populations that are less susceptible to random extinctions.

(c) Human activities like agriculture, urbanization, and road construction dissect continuous habitats into small, isolated fragments. These fragments act as terrestrial "islands" surrounded by a hostile "ocean" of human land-use. Organisms find it difficult to disperse (low immigration) between patches, and small patch sizes support smaller populations that suffer from high extinction rates and edge effects.

(d) Limitations include:
1. It treats the matrix (the surrounding non-reserve land) as completely hostile/uninhabitable (like an ocean), which is not always true.
2. It assumes static equilibrium, ignoring human management, species interactions, and climate change impacts.

(a) [2 marks max]
- Award 1 mark for identifying "Island Delta".
- Award 1 mark for stating both factors: large area (150 \(km^2\)) and close proximity/short distance to mainland (40 km).

(b) [2 marks max]
- Award 1 mark for comparing the richness (Beta has more species than Alpha/45 vs 12) and noting their similar distance to the mainland.
- Award 1 mark for explaining that Beta's larger area supports more habitats/niches and larger populations, reducing extinction rates.

(c) [2 marks max]
- Award 1 mark for outlining that human activity fragments continuous habitat into isolated patches ("islands") surrounded by altered landscapes ("ocean").
- Award 1 mark for explaining how this reduces immigration/colonization between fragments and increases extinction rates within them.

(d) [2 marks max] Award 1 mark for each valid limitation up to a maximum of 2:
- Ignores the quality of the surrounding matrix (the landscape between reserves is not always a complete barrier like water).
- Assumes all species have the same dispersal abilities.
- Focuses on species number rather than species composition/ecological interactions.
- Does not account for active habitat management or climate shifts.

(a) CFC-12 has the highest Global Warming Potential (10,200), meaning it has the highest warming effect per molecule relative to \(CO_2\).

(b) Step 1: Find the absolute increase: \(1,870\text{ ppb} - 700\text{ ppb} = 1,170\text{ ppb}\).
Step 2: Calculate the percentage: \(\frac{1,170}{700} \times 100 = 167.14\%\) (accept answers in the range 167% to 167.14%).

(c) Even though \(CO_2\) has a GWP of only 1, its absolute abundance in the atmosphere is measured in parts per million (ppm), whereas \(CH_4\) and \(N_2O\) are in parts per billion (ppb) and CFCs are in parts per trillion (ppt). The absolute increase of \(CO_2\) since 1750 (135 ppm) is massive compared to the trace increases of other gases, making \(CO_2\) the dominant contributor to overall radiative forcing and global temperature rise.

(d) Three distinct human activities include:
1. Intensive agricultural fertilization: Synthetic fertilizers supply nitrogen to soils, where denitrifying bacteria release nitrous oxide (\(N_2O\)).
2. Livestock farming: Ruminant livestock (such as cows) release methane (\(CH_4\)) through enteric fermentation.
3. Municipal waste management: Landfills provide anaerobic conditions where decomposers generate methane (\(CH_4\)) gas.

(a) [1 mark] Award 1 mark for "CFC-12".

(b) [2 marks max]
- Award 1 mark for showing correct working: \(\frac{1870 - 700}{700} \times 100\).
- Award 1 mark for the correct answer: 167% or 167.1% or 167.14%.

(c) [2 marks max]
- Award 1 mark for noting the vast difference in concentration scales (\(CO_2\) is in parts per million/ppm, while others are in ppb/ppt).
- Award 1 mark for explaining that the total abundance and cumulative radiative forcing of \(CO_2\) far outweigh the other gases despite their higher individual warming potential.

(d) [3 marks max] Award 1 mark for each distinct, valid human activity up to 3:
- Application of synthetic chemical nitrogen fertilizers in farming (releases \(N_2O\)).
- Enteric fermentation from cattle/ruminant agriculture (releases \(CH_4\)).
- Anaerobic decay in flooded rice paddies (releases \(CH_4\)).
- Waste decomposition in municipal landfills (releases \(CH_4\)).
- Fossil fuel extraction / natural gas pipeline leaks (releases \(CH_4\)).
- Fossil fuel combustion or biomass burning (can release \(N_2O\) or \(CH_4\)).

Biomagnification in an aquatic food web occurs through the following steps: 1. Properties of POPs: Persistent Organic Pollutants (POPs) are non-biodegradable and lipophilic (fat-soluble) chemicals, meaning they do not break down easily and accumulate in fatty tissues. 2. Bioaccumulation: Producers absorb POPs from the environment, accumulating them in their tissues. 3. Trophic transfer: Primary consumers eat large quantities of these producers. Since POPs are not excreted, the total load from all prey is transferred to the consumer. 4. Biomagnification: This process repeats up the food chain. Because of the loss of energy and biomass at higher trophic levels, top predators must consume large quantities of prey, resulting in a progressive concentration increase of the toxin at each successive level.

Award 1 mark for each of the following points up to a maximum of 4 marks: - POPs are persistent/non-biodegradable and fat-soluble so they accumulate in fatty tissues rather than being excreted. [1] - Low-trophic-level organisms ingest POPs, which bioaccumulate in their bodies over time. [1] - Higher-trophic-level consumers must eat large amounts of prey due to energy/biomass loss up the food chain. [1] - The pollutant cannot be broken down, so the entire body burden of prey is transferred and concentrated in predator tissues. [1] - This leads to a progressive increase in concentration at each successive trophic level (biomagnification), reaching highest/toxic levels in top predators. [1]

Speciation via geographic isolation occurs through the following steps: 1. Isolation: A physical barrier (e.g., river, mountain range, ocean) splits a population, preventing gene flow between them. 2. Selection: The isolated sub-populations experience different environmental conditions and selection pressures. 3. Divergence: Natural selection favors different traits in each sub-population, and random mutations or genetic drift accumulate, leading to genetic divergence of their gene pools. 4. Reproductive Isolation: Over time, genetic differences prevent successful interbreeding to produce fertile offspring, resulting in the formation of distinct species.

Award 1 mark for each of the following points up to a maximum of 4 marks: - A physical/geographic barrier splits a population, stopping gene flow between sub-populations. [1] - Isolated populations experience different environmental conditions/selection pressures. [1] - Natural selection acts on different variations, causing divergence in the gene pools over time. [1] - Genetic drift/mutations further differentiate the populations. [1] - Genetic differences accumulate until reproductive isolation is achieved, meaning they can no longer interbreed to produce viable, fertile offspring. [1]

Feedback loops are mechanisms where the output of a process affects its input, either amplifying change (positive feedback) or stabilizing the system (negative feedback). In response to rising global temperatures, several positive and negative feedback loops are triggered across oceans and the biosphere. A positive ocean feedback loop is the ice-albedo feedback: warming melts Arctic sea ice, exposing dark ocean water, which absorbs more solar radiation and further warms the ocean and atmosphere, causing more ice to melt. A positive biosphere feedback loop is permafrost melting: higher temperatures thaw permafrost, allowing decomposers to release methane and carbon dioxide, which traps more heat and accelerates warming. Alternatively, forest dieback from droughts releases stored carbon through wildfires, reinforcing warming. A negative ocean feedback loop occurs when warmer sea surface temperatures increase evaporation, leading to increased low-altitude cloud cover; these clouds reflect solar radiation back into space, lowering global temperatures. A negative biosphere feedback loop is the CO2 fertilization effect: increased atmospheric CO2 and warmer temperatures can stimulate plant photosynthesis and growth, causing forests to sequester more carbon dioxide from the atmosphere, which mitigates the greenhouse effect.

Award [1 max] for defining positive and/or negative feedback in the context of climate systems: Positive feedback amplifies or accelerates temperature change, driving the system away from its equilibrium. Negative feedback counteracts temperature change, helping to stabilize the system. Award [3 max] for explaining positive feedback loops (must include both ocean and biosphere examples for full marks): [1] for ocean ice-albedo feedback (ice melt reduces albedo, increases solar absorption, raises temperatures, causes further melt); [1] for biosphere permafrost feedback (warming thaws permafrost, anaerobic decomposition releases methane/CO2, increasing greenhouse effect, raising temperatures); [1] for biosphere forest dieback feedback (warming leads to droughts/fires, releasing carbon dioxide, increasing greenhouse effect). Award [3 max] for explaining negative feedback loops (must include both ocean and biosphere examples for full marks): [1] for ocean cloud feedback (warming increases ocean evaporation, leading to low-level clouds, which increase planetary albedo and reflect incoming solar radiation, causing cooling); [1] for biosphere fertilization feedback (higher temperatures and CO2 stimulate plant growth, increasing carbon uptake/sequestration via photosynthesis, which reduces atmospheric carbon levels and cools the climate). Note: Accept other valid, scientifically accurate feedback mechanisms involving oceans or the biosphere.

Eutrophication begins when agricultural runoff containing high concentrations of nitrates and phosphates enters a freshwater lake. This nutrient enrichment triggers rapid growth of algae, leading to an algal bloom on the surface. The dense algal layer blocks sunlight from reaching submerged aquatic plants, preventing photosynthesis and causing them to die. As algae and plants die, populations of aerobic decomposers (bacteria) increase rapidly to break down the organic matter. These bacteria consume dissolved oxygen in the water, causing biochemical oxygen demand (BOD) to rise. The resulting depletion of dissolved oxygen (anoxia) leads to the suffocation and death of fish and other aerobic aquatic organisms, severely reducing biodiversity. An ecocentric management strategy, such as promoting organic farming practices or restoring natural riparian buffer zones, focuses on changing human behavior to prevent nutrient runoff at the source. This is highly effective because it prevents pollution from ever entering the system and is ecologically sustainable. However, it can be slow to implement, difficult to enforce globally, and may initially reduce crop yields. In contrast, a technocentric management strategy, such as mechanical aeration of the lake or dredging nutrient-rich sediments, relies on technology to treat the symptoms of eutrophication. This is highly effective for rapid restoration of critical oxygen levels and immediate preservation of fish populations. However, it is very expensive, requires continuous energy inputs, and fails to address the agricultural source of the pollution, meaning eutrophication will recur once the treatment stops.

Award up to [3 max] for explaining the process of eutrophication: [1] for nutrient enrichment (agricultural runoff containing nitrates/phosphates entering the lake); [1] for algal bloom blocking light, preventing photosynthesis and killing submerged plants; [1] for decomposers multiplying and consuming dissolved oxygen (BOD increases); [1] for anoxia leading to the death of fish and other aquatic organisms. Award up to [2 max] for evaluating an ecocentric strategy (e.g., organic farming, riparian buffers): [1] for describing the strategy (e.g., replacing synthetic fertilizers with compost, planting forest buffers); [1] for evaluating its effectiveness (effective because it addresses the root cause of pollution at the source and is sustainable, but limited by slow behavioral change and potential initial drops in agricultural productivity). Award up to [2 max] for evaluating a technocentric strategy (e.g., aeration, dredging, chemical precipitation): [1] for describing the strategy (e.g., pumping oxygen into the lake, physically removing sediment); [1] for evaluating its effectiveness (effective for rapid, localized recovery of oxygen levels, but ineffective long-term because it only treats symptoms, is highly expensive, and does not stop ongoing runoff).

An ecocentric approach focuses on changing human behavior and respecting the intrinsic value of water systems. Ecocentrics advocate for reducing water footprints through lifestyle changes, such as adopting plant-based diets which require significantly less water than meat-intensive diets. They support local, small-scale rainwater harvesting, greywater recycling, and organic farming techniques that prevent agricultural runoff. Ecocentrics are generally opposed to large-scale dams because they disrupt natural river systems and displace local communities. An anthropocentric approach seeks a balance by managing water resources through government regulations, international treaties, and economic policies. Anthropocentrics support the implementation of water tariffs to encourage conservation, the enforcement of water quality standards, and regional cooperation agreements for shared river basins (like the Nile or Mekong). They believe humans have a right to clean water but must manage it sustainably through democratic governance and public education. A technocentric approach relies on technological innovation and economic growth to solve water scarcity. Technocentrics advocate for increasing water supply using high-tech methods such as seawater desalination plants, large-scale dam construction to store surface water, cloud seeding to induce precipitation, and the development of genetically modified (GM) drought-resistant crops. They see water as a resource to be managed and maximized through engineering. In evaluation, while technocentric solutions can rapidly provide freshwater in arid regions, they are highly energy-intensive and expensive, making them less viable for poorer nations. Ecocentric strategies are highly sustainable but difficult to enforce globally due to deeply ingrained consumption habits. Therefore, a holistic approach combining technocentric supply-side solutions and ecocentric demand-side behavioral changes, coordinated by anthropocentric policy, is the most viable path to ensuring global water security.

Award up to 7 marks for discussing the three environmental value systems (EVSs) and their approaches to water management. Award up to 3 marks for ecocentric perspectives, including specific examples like lifestyle changes, rain harvesting, and opposition to dams. Award up to 3 marks for anthropocentric perspectives, including examples like water pricing, international treaties, and national regulations. Award up to 3 marks for technocentric perspectives, including examples like desalination, cloud seeding, and GM crops. Award up to 2 marks for a balanced evaluation or conclusion that compares the viability, costs, and ethical considerations of these different approaches to show which combination is most effective for water security. Maximum of 9 marks overall.

Technocentric approaches to climate change mitigation focus on technology and engineering to reduce greenhouse gases or manage solar radiation. Examples include Carbon Capture and Storage (CCS) at power plants, large-scale transition to nuclear and renewable energy grids, and geoengineering proposals like stratospheric aerosol injection. The viability of technocentrism lies in its compatibility with the current global capitalist economic system; it does not require individuals to drastically change their high-consumption lifestyles, making it politically and socially easier to implement. However, its limitations include high economic costs, the risk of technological lock-in, the potential for unforeseen global ecological side-effects (especially with geoengineering), and the fact that it does not address the underlying causes of resource depletion. In contrast, ecocentric approaches focus on shifting human values to live within ecological limits. Examples include widespread reforestation and rewilding to enhance natural carbon sinks, transitioning to localized organic agriculture, and promoting a degrowth economic model that minimizes resource consumption. The viability of ecocentrism lies in its focus on root causes, creating a highly resilient and sustainable biosphere without hazardous technological interventions. However, ecocentrism faces extreme practical limitations: it requires a radical shift in global political and economic systems, which is highly resisted by powerful industries and consumer populations, and cannot be implemented rapidly enough to avoid immediate tipping points. In conclusion, while technocentric solutions offer rapid, scalable tools necessary to stabilize global temperatures in the short term, they are not a complete long-term solution on their own. For true viability, technocentric technologies must be integrated with ecocentric values that limit overall global resource consumption and promote ecological stewardship.

Award up to 7 marks for the analysis of technocentric and ecocentric mitigation strategies. Award up to 4 marks for technocentric arguments, clearly explaining strengths (e.g., maintaining economic growth, scalability of renewables) and weaknesses (e.g., high costs of CCS, risks of geoengineering). Award up to 4 marks for ecocentric arguments, clearly explaining strengths (e.g., addressing root causes, co-benefits of reforestation) and weaknesses (e.g., political resistance, slow implementation). Award up to 2 marks for a structured evaluation that directly addresses the prompt 'to what extent' and synthesizes the two views into a reasoned conclusion. Maximum of 9 marks overall.