Exercises: Sustainable development

Define sustainable development in your own words and describe a decision that your local council could take (regarding transport, energy, or waste management) that is consistent with this concept, justifying your answer.

Explain what the ecological footprint measures and what unit it is expressed in. Name two everyday activities that increase it and two that reduce it, giving reasons for each.

Differentiate between the concepts of environmental impact and ecological footprint, using the construction of a major motorway through a rural area as an example.

Define biocapacity and explain how it differs from the ecological footprint, indicating the relationship between the two when a territory lives beyond its means.

Explain what an environmental indicator is and what advantage there is in the ecological footprint expressing very different impacts in a single unit (the global hectare), as well as one limitation of reducing everything to a single number.

Name the main components of the ecological footprint (carbon footprint, cropland, grazing land, fishing grounds, forest and land occupied by infrastructure) and explain what two of them, of your choice, consist of.

Order these ways of getting to school from smallest to largest ecological footprint and justify the order: cycling, driving alone, taking the city bus and car-sharing between four people.

Explain what a country's ecological deficit is and discuss what it implies that Spain has a persistent deficit: where do the resources that its own territory does not produce come from?

The diagram compares the ecological footprint and available biocapacity per inhabitant of a city. Calculate its ecological deficit per inhabitant (the section marked with '?') and explain what this result means.

Order these three diets from smallest to largest ecological footprint and justify the order based on the land area, water, and energy each requires: vegetarian diet, diet rich in beef, and Mediterranean diet.

Earth Overshoot Day (the date on which humanity exhausts the resources that the planet regenerates in one year) has moved from late December in 1970 to late July today. Interpret what this date indicates, what trend its earlier arrival reflects, and how it relates to humanity's ecological footprint.

A city has an ecological footprint of $3{,}2\ \text{gha}$ per inhabitant and a biocapacity of its own of $1{,}1\ \text{gha}$ per inhabitant. a) Calculate its ecological deficit per inhabitant. b) Explain how it is possible for the city to keep functioning despite this deficit (importing biocapacity) and which territories pay the difference.

The carbon footprint (the area of forest needed to absorb the emitted $\text{CO}_2$) accounts for more than half of the ecological footprint of rich countries. Explain which activities feed it and why decarbonising energy would be the measure that most reduces the total footprint.

Producing $1\ \text{kg}$ of beef requires about $15\,000\ \text{L}$ of water and producing $1\ \text{kg}$ of wheat about $1\,500\ \text{L}$. Calculate the water saved in a year if a person replaces a weekly kilo of beef with a kilo of wheat, and comment on what this "virtual water" contained in the diet represents.

Explain what the ecological debt that rich countries hold with impoverished countries is, and relate it to the flows of raw materials (minerals, food, energy) and to the location of environmental impacts.

Two people with the same income can have very different ecological footprints. Identify three life decisions (type of housing and its heating and cooling, usual means of transport, diet) and discuss, for each one, which option reduces the footprint most and why.

A peri-urban municipality of $25\,000$ inhabitants records an average ecological footprint of $4,5\ \text{gha/capita}$, broken down into: carbon footprint from transport and energy ($58\ \%$), pasture and cropland footprint from food ($26\ \%$), forest products ($10\ \%$), and built-up land ($6\ \%$). To reduce the total footprint by $20\ \%$ in ten years, the city council proposes focusing almost the entire budget on widening sidewalks in the historic center and planting trees in a peri-urban park.

1. a) Quantitatively and qualitatively evaluate the municipal proposal based on the footprint breakdown. Is it sufficient to achieve the $20\ \%$ target? Justify your deduction.
2. b) Design an alternative strategy of three structural measures that primarily target the two highest-weight components (mobility/energy and food system), specifying for each one which category of global hectares it would directly reduce.
3. c) Analyze two socioeconomic obstacles or citizen resistance that could hinder the implementation of your measures and propose a feasible solution to overcome them without undermining the ecological goal.

Analyze the following socio-ecological indicators for three fictitious countries:

• Country A: GDP per capita = $44\,000\ \text{€}$; Ecological footprint = $6,5\ \text{gha/capita}$; Water footprint = $2\,400\ \text{m}^3\text{/capita/year}$; HDI = $0,93$.

• Country B: GDP per capita = $17\,000\ \text{€}$; Ecological footprint = $2,2\ \text{gha/capita}$; Water footprint = $1\,150\ \text{m}^3\text{/capita/year}$; HDI = $0,82$.

• Country C: Suffered a major industrial disaster with toxic spills that flooded a natural park; during the subsequent two years, its GDP per capita grew by $3,8\ \%$ annually due to decontamination work, compensation payments, and infrastructure reconstruction.

1. a) Using the case of Country C, refute the statement that «continuous GDP growth is synonymous with sustainable development». Identify which structural flaw of traditional economic accounting is exposed.
2. b) Compare the profiles of countries A and B. Argue which of the two is closer to a model of genuine sustainability when relating quality of life to ecosystem burden.
3. c) Select two complementary indicators (for example, the Planetary pressures-adjusted Human Development Index and the Water or Material Footprint) and technically justify what critical information they provide that GDP completely ignores.

The average biocapacity of the planet is approximately $1,6\ \text{gha/capita}$. In a developed country (A), the average ecological footprint reaches $4,7\ \text{gha/capita}$, while its own territorial biocapacity is $1,4\ \text{gha/capita}$. In a developing country (B), the footprint is $1,1\ \text{gha/capita}$ and its territorial biocapacity is $2,6\ \text{gha/capita}$.

1. a) Calculate how many planet Earths would be needed if the entire world population adopted the consumption pattern of country A. With that data, calculate with justification on which day of the year (Earth Overshoot Day) humanity would exhaust the regenerative resources of the planet under such a pattern.
2. b) Calculate the ecological deficit or reserve of both countries (territorial biocapacity minus footprint). Explain, in biogeochemical and trade terms, how country A manages to maintain consumption far exceeding its local biological capacity without immediately collapsing.
3. c) Assess the outcome from the perspective of global equity and ecological debt: what long-term biophysical consequences does the consumption pattern of country A have for country B and for the biosphere as a whole?

The total biocapacity of the planet is about $12\,000$ million global hectares for a world population of $8\,000$ million people. However, scientific consensus in conservation establishes that at least $20\ \%$ of this biocapacity must be safeguarded to preserve the habitats of wild species without direct human interference.

1. a) Calculate the actual biocapacity per capita available for the human species under this ecological reserve principle.
2. b) Taking the average ecological footprint in Spain ($4,0\ \text{gha/capita}$) as a reference, calculate the exact percentage by which this footprint exceeds the available biocapacity per capita calculated in the previous section.
3. c) A technical report claims that improving energy efficiency in buildings and transport by $25\ \%$ will be sufficient to close this gap. Refute this claim by demonstrating why an isolated technical improvement does not resolve the excess footprint in Spain, and formulate three non-individual structural transformations (covering the agri-food, urban planning, and industrial sectors) to comprehensively reduce the gap.

A large intensive agro-industrial complex located in a Mediterranean basin claims in its environmental report that it has reduced its ecological footprint by $30\ \%$ in five years because it electrified its machinery using solar energy and replaced plastic packaging with certified forest cellulose derivatives. However, the technical report of the basin warns that during that same period the company depleted local aquifers due to overexploitation of irrigation wells, increased nitrate contamination in groundwater, and caused a $70\ \%$ decline in steppe bird populations due to the removal of hedges and field margins.

1. a) Explain why the standard ecological footprint methodology does not reflect the severe impact on the aquifer or on the local wildlife. Identify two inherent biases or limitations of this indicator when assessing comprehensive environmental health.
2. b) Select two complementary indicators (such as the grey water footprint or biological integrity/biodiversity indices) and justify how they would accurately measure the impacts that the ecological footprint has omitted in this case.
3. c) Design a proposal for a sustainability "dashboard" for this agricultural region: define three irreplaceable biophysical axes and establish for each one a criterion or threshold that prevents improvement in one variable from masking the critical degradation of another.

An urban association of municipalities sets a goal of achieving net-zero emissions by 2035. In its greenhouse gas inventory, it records $200\,000\ \text{t CO}_2\text{e/year}$, originating from residential heating, cooling, and electricity ($45\ \%$), fossil-fuel motorized transport ($35\ \%$), and waste management and indirect consumption ($20\ \%$). The plan proposed by the managers consists of reducing emissions by $5\ \%$ through awareness campaigns and purchasing carbon credits on the international market (financing forest monocultures on other continents) to offset the remaining $190\,000\ \text{t CO}_2\text{e/year}$.

1. a) Evaluate this plan according to the climate mitigation hierarchy. Reason why offsetting before or in a greater proportion than reducing constitutes a serious technical and methodological failure.
2. b) Critically analyze the massive purchase of forest carbon credits, pointing out two characteristic biophysical or governance problems (for example, permanence against disturbances, questionable additionality, or emissions leakage).
3. c) Redesign the association's decarbonization plan by establishing a deep, structural reduction measure for each of the four key sectors (buildings, urban mobility, resource management/consumption, and local natural carbon sinks), justifying its technical effectiveness.

A regional mobility plan subsidized the mass purchase of highly efficient internal combustion vehicles that consume $40\ \%$ less fuel per $100\ \text{km}$. Five years later, total carbon emissions from the transport sector in the region have not decreased; instead, they have increased by $5\ \%$. Analysis reveals that, as the cost per kilometer fell, the average annual distance traveled per user increased from $12\,000\ \text{km}$ to $21\,000\ \text{km}$, and many households acquired a second vehicle.

1. a) Explain the socio-ecological phenomenon illustrated by this case (Jevons paradox or rebound effect). Demonstrate with a quantitative calculation whether the annual fuel emissions of an average driver increased or decreased after the change and by what exact percentage.
2. b) Generalize this reasoning: why is relying exclusively on technological eco-efficiency usually insufficient to contract the absolute ecological footprint if sufficiency measures are not implemented?
3. c) Design a combined public strategy of three instruments (one regulatory absolute limit, one disincentivizing fiscal measure, and one urban planning measure) capable of capturing technical efficiency gains without triggering the rebound effect.

A mining company requests authorization to exploit an open-pit lithium deposit over a karstic lagoon and its associated aquifer. The project will generate $900$ stable jobs over $20$ years and substantial tax revenues for the region. The company argues that the loss of the wetland will be fully offset by endowing a trust fund for vocational training, building a technology park, and creating an artificial recreational lake in another area.

1. a) Analyze the company's proposal under the frameworks of weak sustainability and strong sustainability. Identify what theoretical assumption the company makes regarding the substitution of "natural capital" with "manufactured and human capital".
2. b) From an ecological and biogeochemical perspective, argue why the karstic lagoon and its aquifer must be classified as "critical natural capital" and not as a resource replaceable by artificial infrastructure or economic returns.
3. c) If you were part of the environmental impact assessment technical team, what ruling would you issue regarding the project's viability? Justify your stance based on the precautionary principle and ecological irreversibility in the face of pressures for immediate socioeconomic gain.