Question 1: Define 'carbon footprint' in the context of climate change.

Answer: The total amount of greenhouse gases, particularly carbon dioxide, emitted directly or indirectly by human activities.

Question 2: Explain how burning fossil fuels contributes to the greenhouse effect.

Answer: Burning fossil fuels releases carbon dioxide into the atmosphere, increasing the greenhouse effect and trapping more heat.

Question 3: Describe one way in which individuals can reduce their carbon footprint.

Answer: Using public transport, cycling, or reducing energy consumption at home.

Question 1: Calculate the amount of CO₂ emitted when 50 litres of petrol is combusted. (Given: 1 litre of petrol releases approximately 2.3 kg of CO₂.)

Answer: CO₂ emissions = volume of petrol (litres) × emission factor (kg CO₂/litre) = 50 × 2.3 = 115 kg

Question 2: A car travels 150 km and consumes 10 litres of petrol. Calculate the carbon footprint for this trip, given that burning 1 litre of petrol produces 2.3 kg of CO₂.

Answer: Total CO₂ = fuel used (litres) × emission factor = 10 × 2.3 = 23 kg

Question 1: Describe a simple experimental method to estimate the amount of CO₂ produced from baking bread in a school laboratory setting.

Answer: Use a gas collection apparatus to measure the volume of CO₂ released during baking, and record the volume over time to estimate total emissions.

Question 2: Identify two variables that need to be controlled in an experiment measuring CO₂ emissions from combustion.

Answer: Amount of fuel burned and oxygen supply.

Question 3: State one safety precaution to consider when conducting experiments involving combustion in the lab.

Answer: Ensure proper ventilation and keep a fire extinguisher nearby.

Question 1: A study reports that an average household's annual carbon footprint is 7 tonnes of CO₂. If the household reduces its emissions by 20%, how much CO₂ will they emit after reduction?

Answer: New emissions = 7 tonnes × (1 - 0.20) = 5.6 tonnes

Question 2: Interpret what a 15% increase in greenhouse gases from a factory indicates regarding its carbon footprint and potential environmental impact.

Answer: A 15% increase suggests a higher carbon footprint, leading to more heat trapping in the atmosphere, which can accelerate global warming and climate change.

Question 1: Explain the relationship between energy consumption, fossil fuel use, and carbon footprint. (6 marks)

Answer: Higher energy consumption often involves the burning of fossil fuels like coal, oil, and natural gas, which releases CO₂ into the atmosphere. This increases an individual's or organisation's carbon footprint, contributing to the greenhouse effect and climate change. Reducing energy use or switching to renewable sources can lower the carbon footprint.

Question 1: Identify one technological innovation designed to reduce industrial carbon emissions and briefly explain how it works.

Answer: Carbon capture and storage (CCS) technology captures CO₂ emissions from factories and stores it underground to prevent it from entering the atmosphere.

Question 2: Suggest a change in daily life that could significantly lower an individual's carbon footprint over a year.

Answer: Reducing air travel and using more sustainable modes of transport like cycling or public transport.