Question 1: Define a greenhouse gas and name three common greenhouse gases present in Earth's atmosphere.

Answer: A greenhouse gas is a gas that absorbs and emits infrared radiation, trapping heat in the atmosphere. Common greenhouse gases include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).

Question 2: Explain how greenhouse gases contribute to the greenhouse effect and global warming.

Answer: Greenhouse gases absorb infrared radiation emitted from Earth's surface and re-emit it in all directions, including back towards the surface. This process traps heat in the atmosphere, leading to the greenhouse effect. An increase in these gases enhances this effect, contributing to global warming.

Question 3: Calculate the increase in CO2 concentration if a factory emits 500 kg of CO2 daily, and the atmospheric concentration increases by 0.02 ppm per day. Show your working (use 1 ppm CO2 ≈ 7.8 Gt).

Answer: Daily increase in Gt = 500 kg × (1 Gt / 1,000,000,000 kg) = 0.0005 Gt. Since 0.02 ppm corresponds to 0.02 × 7.8 Gt = 0.156 Gt, the factory's daily emissions contribute to this increase proportionally. Exact increase in ppm per day = (0.0005 Gt / 7.8 Gt) × 1 ppm ≈ 0.000064 ppm.

Question 4: Identify two variables that could affect the rate at which greenhouse gases are absorbed or emitted in an environmental experiment.

Answer: Temperature and the presence of catalysts or absorption materials.

Question 5: Which of the following gases is NOT considered a significant greenhouse gas? A) Carbon dioxide B) Oxygen C) Methane D) Nitrous oxide

Answer: Oxygen

Question 6: Fill in the blank: The primary human activities that increase greenhouse gases in the atmosphere include __________ and burning fossil fuels.

Answer: deforestation

Question 7: Describe one practical method to reduce the emission of greenhouse gases from vehicles.

Answer: Using alternative fuels such as electric power or biofuels, improving fuel efficiency, or switching to public transportation.

Question 8: Analyzing the data: If a city’s CO2 emissions increased from 100 million tonnes to 120 million tonnes over five years, what is the percentage increase in emissions?

Answer: Percentage increase = [(120 - 100) / 100] × 100 = 20%

Question 9: Explain why methane is considered a more potent greenhouse gas than carbon dioxide despite its lower concentration in the atmosphere.

Answer: Methane is considered more potent because it has a much higher global warming potential (GWP). Over a 20-year period, methane can be over 80 times more effective at trapping heat than carbon dioxide. Its strong absorption of infrared radiation makes it a significant contributor to the greenhouse effect despite its lower concentration.

Question 10: Discuss the importance of international agreements, such as the Paris Agreement, in controlling greenhouse gas emissions.

Answer: International agreements like the Paris Agreement are crucial because they set targets for countries to reduce their greenhouse gas emissions collectively. They promote cooperation, technology sharing, and policy development to mitigate climate change impacts globally. Such agreements also encourage nations to commit to sustainable practices and monitor progress towards emission reduction goals.