Understanding Global Warming and Greenhouse Gases

The question asks us to evaluate two statements regarding global warming and its causes and determine the relationship between them.

Analyzing Statement I: Global Warming Definition

Statement I says: "Global warming signifies the rise in global surface temperature."

This statement defines global warming as an increase in the average temperature of the Earth's surface and atmosphere. This is a widely accepted definition used in climate science. Historical data and ongoing measurements show a clear trend of rising global temperatures, especially since the industrial revolution. Therefore, Statement I is true.

Analyzing Statement II: Greenhouse Gases and Temperature Rise

Statement II says: "The increase of concentration of greenhouse gases in the atmosphere causes the rise in global surface temperature."

This statement points to the role of greenhouse gases in driving the temperature increase. Greenhouse gases, such as carbon dioxide (\(CO_2\)), methane (\(CH_4\)), nitrous oxide (\(N_2O\)), and water vapor, trap heat in the Earth's atmosphere through a process known as the greenhouse effect. When the concentration of these gases increases, more heat is trapped, leading to a warming of the planet's surface and lower atmosphere. Scientific evidence strongly supports this causal link. Therefore, Statement II is also true.

Evaluating the Relationship Between Statements I and II

We have determined that both Statement I and Statement II are true individually. Now we need to consider if Statement II is the correct explanation for Statement I.

Statement I describes the phenomenon (rise in global surface temperature - global warming).

Statement II provides a key cause for this phenomenon (increase in greenhouse gas concentration). The mechanism described in Statement II (enhanced greenhouse effect due to increased gases) directly leads to the outcome described in Statement I (global warming). Therefore, Statement II provides a correct and fundamental explanation for why global warming is happening.

Examining the Options

Let's look at the given options based on our analysis:

• Option 1: Both the statements are individually true and Statement II is the correct explanation of Statement I. (Matches our analysis)
• Option 2: Both the statements are individually true but Statement II is not the correct explanation of Statement I. (Contradicts our finding that Statement II explains Statement I)
• Option 3: Statement I is true but Statement II is false. (Contradicts our finding that Statement II is true)
• Option 4: Statement I is false but Statement II is true. (Contradicts our finding that Statement I is true)

Based on our evaluation, both statements are true, and Statement II explains Statement I. This aligns with Option 1.

Conclusion

Statement I accurately describes global warming as a rise in global surface temperature. Statement II correctly identifies the increase in greenhouse gas concentration as a cause for this temperature rise. The increase in greenhouse gases trapping more heat is indeed the primary mechanism explaining the observed global warming.

Therefore, both statements are individually true, and Statement II correctly explains Statement I.

Revision Table: Global Warming Concepts

Additional Information on Climate Change

Global warming is a key aspect of climate change, which refers to broader shifts in climate patterns, including changes in precipitation, sea levels, and frequency of extreme weather events. While natural factors influence climate, the current rapid warming trend is overwhelmingly attributed to human activities that release greenhouse gases into the atmosphere.

• Major sources of increased greenhouse gases include burning fossil fuels (coal, oil, natural gas) for energy, deforestation, industrial processes, and agriculture.
• The increase in global surface temperature has various impacts, including melting ice sheets and glaciers, rising sea levels, altered ecosystems, and changes in agricultural productivity.
• Scientists use climate models to project future temperature increases based on different scenarios of greenhouse gas emissions.
• Efforts to mitigate climate change focus on reducing greenhouse gas emissions, transitioning to renewable energy sources, improving energy efficiency, and carbon capture technologies.