Question: Which human activity is correctly paired with the greenhouse gas that it increases?
A) Burning fossil fuels – Carbon dioxide
B) Deforestation – Methane
C) Agriculture – Chlorofluorocarbons (CFCs)
D) Industrial processes – Water vapor
Answer: A) Burning fossil fuels – Carbon dioxide
Explanation: Burning fossil fuels, such as coal, oil, and natural gas, releases carbon dioxide (CO2) into the atmosphere. This is because fossil fuels contain carbon that has been stored underground for millions of years, and when they are burned, the carbon is released into the air as CO2. Deforestation, on the other hand, can increase methane (CH4) levels in the atmosphere because when trees are cut down and left to decompose, they release methane. Agriculture is also a significant contributor to greenhouse gas emissions, but it is mainly associated with nitrous oxide (N2O), which is released from fertilizer use and livestock manure. Finally, industrial processes do not directly release greenhouse gases, but they can contribute to their production, such as through the manufacturing of products that require large amounts of energy or the use of chemicals that deplete the ozone layer and indirectly contribute to global warming. Water vapor is a naturally occurring gas in the atmosphere, and while it is a greenhouse gas, it is not directly influenced by human activities.
Question: Which gas contributes most to human-caused global warming?
A) Carbon dioxide (CO2)
B) Methane (CH4)
C) Nitrous oxide (N2O)
D) Water vapor (H2O)
Answer: A) Carbon dioxide (CO2)
Explanation: While all of these gases are greenhouse gases, which means they trap heat in the atmosphere and contribute to global warming, carbon dioxide is the most significant contributor to human-caused global warming. This is because CO2 emissions come from burning fossil fuels, which is a primary activity of modern civilization. Additionally, carbon dioxide has a much longer lifespan in the atmosphere than other greenhouse gases, so once it is released, it can remain in the atmosphere for centuries.
Methane and nitrous oxide are also potent greenhouse gases but are released in smaller quantities than CO2. Methane is primarily emitted by agricultural activities, such as livestock farming and rice cultivation, while nitrous oxide comes from fertilizer use, industrial processes, and other human activities.
Water vapor is not directly influenced by human activities but is a natural greenhouse gas that contributes to the Earth’s greenhouse effect. However, water vapor levels in the atmosphere are primarily influenced by temperature, so it acts as a feedback mechanism rather than a primary cause of global warming.