Technology, Ethics and Sustainability: free practice, theory and problems

1. Sustainability

What is it about?

Sustainability is about understanding and reducing the total impact a product, service or activity has on the environment and society – from the extraction of raw materials to when it eventually becomes waste. For an engineer this isn't just ethics, it's also arithmetic: you need to be able to quantify emissions and energy use in order to compare alternatives and show that a measure actually works.

Concepts and formulas

• Life cycle assessment (LCA): maps the environmental impact "from cradle to grave" (raw materials → production → transport → use → disposal), or "cradle to cradle" if the materials go back into the loop.
• Functional unit: the common reference products are compared per (e.g. "transporting one person 1 km"), essential for a fair comparison.
• Carbon footprint / greenhouse gas account: the sum of emissions converted to CO₂-equivalents, $E = \sum_i A_i\cdot EF_i$, where $A_i$ is activity data (e.g. km driven, kWh used) and $EF_i$ is the emission factor for that source.
• CO₂-equivalents (GWP): greenhouse gases other than CO₂ (e.g. methane, nitrous oxide) are weighted by how much more warming effect they have than CO₂ over a given time horizon (Global Warming Potential, GWP). Total in CO₂-equivalents: $CO_2e = \sum_i m_i\cdot GWP_i$.
• Scope 1, 2 and 3: direct emissions (1), emissions from purchased energy (2), and the rest of the value chain's indirect emissions (3).
• Circular economy: keep materials and products in use as long as possible, roughly in priority order: reduce use → repair → reuse → recycle the material.
• Energy payback time: embodied energy in a product divided by the annual energy savings or generation, giving the number of years before the product has "paid back" its own production energy.

How to solve the problems

1. Identify the activity data (amount, distance, energy) and find the right emission or GWP factor.
2. Multiply the activity data by the factor for each source, and sum if there are several sources or gases.
3. Watch the units – emission factors are often given in grams, while the answer often needs to be in kilograms or tonnes.
4. For life cycle and energy questions: check whether you are comparing one phase (e.g. use) or the whole life cycle, and use the same functional unit for both alternatives you compare.

Example

A car trip is 350 km long, and the car emits 120 g CO₂ per km. How many kg CO₂ does the trip emit in total?

1. Total emissions: $E = 350\cdot 120 = 42.000$ g.
2. Convert to kg: $42.000/1000 = 42$ kg CO₂.

Answer: 42 kg CO₂.

Common mistakes

• Comparing two products without a common functional unit (e.g. "per kilogram" versus "per unit").
• Forgetting to convert between grams, kilograms and tonnes in emission calculations.
• Assuming recycling is always the best option – reuse and reducing consumption usually rank higher in the waste hierarchy.
• Ignoring the rebound effect: a more energy-efficient solution can lead to more use, eating up part of the benefit.

Concepts in this part

Practise sustainability in the app →

2. Ethics and responsibility

What is it about?

Engineers are constantly making decisions that affect other people, society and the environment – often long before the consequences become visible. Ethics gives you tools for thinking systematically through such decisions, in addition to the law, which only sets a minimum requirement. Professional codes (e.g. from engineering associations) state that the engineer's responsibility for public safety, health and welfare comes before the client's interests.

Concepts and formulas

• Consequentialist ethics (e.g. utilitarianism): judges an action by the outcomes it leads to – the greatest good for the greatest number.
• Duty ethics (e.g. Kant): judges an action by whether it follows a moral duty or rule, regardless of the outcome.
• Virtue ethics: emphasizes what character and qualities a good person or engineer has, not just individual actions.
• The precautionary principle: lack of full scientific certainty must not be used as a reason to postpone measures against serious or irreversible harm.
• Stakeholder analysis: mapping who is affected by, or can affect, a project – done early to catch conflicts before they become costly.
• Conflict of interest: when personal interests (financial, professional, relational) can influence a professional judgment. Handled by disclosing it or stepping aside from the matter (recusal).
• Whistleblowing: speaking up about wrongdoing, usually through internal channels first, and externally if that doesn't work.
• Dual use: the same technology can be used for both civilian and military purposes, or for both good and harmful ends.
• Responsible innovation (RRI): considering social and ethical consequences early in the development process, not as an afterthought.
• Privacy (GDPR): key principles are data minimization (only collect what is needed) and purpose limitation.

How to solve the problems

1. Map the facts and who is affected (stakeholder analysis).
2. Identify relevant principles: legal requirements, professional codes (safety first), privacy rules.
3. Consider the case from several ethical angles: consequences (utilitarian), duties/rules (deontological), and what character a good engineer would show (virtue ethics).
4. Decide on an action, document the reasoning, and use internal channels before considering external whistleblowing.

Example

You discover a software bug in a medical device right before launch. In rare cases the bug can cause an incorrect dose. The project manager is pushing to launch as planned. What do you do?

1. Stakeholders: patients (highest risk), hospitals, employer, colleagues.
2. Principle: codes of engineering ethics put safety ahead of deadlines and cost.
3. Consequence assessment: the risk of patient harm outweighs the cost of a delay.
4. Conclusion: you report it internally immediately and insist that the bug is fixed, or that the risk is documented and accepted by the right authority, before launch; if this is ignored, you consider escalating further or whistleblowing externally.

Answer: safety before deadline – report internally first, escalate or blow the whistle if it isn't heard.

Common mistakes

• Assuming "if it's legal, it's automatically ethical" – the law is a minimum requirement, not an ethical ceiling.
• Only considering the consequences for your own company, forgetting other affected parties.
• Treating whistleblowing as the first step instead of the last resort after internal channels have been tried.
• Assuming technology is neutral and that the engineer has no responsibility for how it is used.

Concepts in this part

Practise ethics and responsibility in the app →

3. Life cycle and carbon accounting

What is it about?

How environmentally friendly is a product really? An electric car has no exhaust, but the battery causes large emissions when it is made. A life cycle assessment (LCA) adds up the emissions through the whole life of the product, from raw material to waste, so you can compare solutions fairly.

Concepts and formulas

• Life cycle phases: raw material extraction → production → transport → use → end of life (recycling or waste).
• Functional unit: what you compare on, for example "transporting one person 1 km" or "heating a house for one year". Without a common functional unit the comparison is meaningless.
• Emission factor: kg CO₂ equivalents per unit (per kg of steel, per km, per kWh). The emission is the amount times the factor:

• CO₂ equivalents (CO₂e): other greenhouse gases are converted using the global warming potential GWP. Methane has a GWP of about 28, so 1 kg of methane ≈ 28 kg CO₂e.
• Scope 1, 2 and 3: direct emissions from your own operations (1), from purchased energy (2) and the rest of the value chain, such as purchased goods and customers' use (3).
• Payback time for a climate measure: extra emissions from production divided by the annual saving.

How to solve the problems

1. Decide the functional unit and which phases are included.
2. Multiply each amount by its emission factor, and add up.
3. Watch the units: g or kg, kWh or MWh, per year or in total.

Example

A heat pump causes 300 kg CO₂e in production and saves 150 kg CO₂e per year.

1. Payback time: $300/150 = 2$ years.
2. Over a 15-year lifetime it saves $15\cdot 150 - 300 = 1950$ kg CO₂e.
3. The measure pays off for the climate after two years.

Common mistakes

• Comparing products without a common functional unit.
• Looking only at the use phase and forgetting production (or the other way round).
• Mixing grams and kilograms, or emissions per year and in total.

Concepts in this part

Practise life cycle and carbon accounting in the app →