Question

students learn that carbon dioxide is a greenhouse gas that contributes to climate change. they want to identify the sources of carbon dioxide emissions in order to make a plan to reduce their towns impact on climate change. which two processes contributed most to the changes in carbon dioxide concentrations since 1985? a. respiration of a growing population b. transportation of goods and people c. manufacturing of materials like cement d. development of renewable energy sources e. expansion of public transportation services

Explanation:

1. Analyze Option A: Respiration of a growing population releases CO₂, but the rate of change in human respiration - related CO₂ emissions since 1985 is not the major contributor compared to industrial and transportation - related emissions.
2. Analyze Option B: Transportation of goods and people, especially with the increase in the use of fossil - fuel - powered vehicles since 1985, is a major source of CO₂ emissions. The burning of fossil fuels in cars, trucks, etc., releases a large amount of CO₂.
3. Analyze Option C: Manufacturing of materials like cement involves processes that release a significant amount of CO₂. The cement industry is a major industrial source of CO₂ emissions, and its growth since 1985 has contributed greatly to the increase in CO₂ concentrations.
4. Analyze Option D: Development of renewable energy sources helps to reduce CO₂ emissions, so it is not a contributor to the increase in CO₂ concentrations.
5. Analyze Option E: Expansion of public transportation services, if using cleaner energy or more efficient systems, is more likely to reduce CO₂ emissions rather than increase them. So it is not a major contributor to the increase in CO₂ concentrations.

Answer:

B. transportation of goods and people, C. manufacturing of materials like cement