Sustainability and Climate Risk (SCR) — Question 19

A climate scientist develops a presentation on modern climate change for a group of policymakers.
What observation does the scientist include in the presentation that provides evidence of human attribution to current climate change?

Answer options

• A. Atmospheric CO2 with isotopes consistent with fossil fuel emissions have increased since the mid-20th century.
• B. Glacial ice records indicate atmospheric CO2 increased by 135 parts per thousand since the Industrial Revolution.
• C. In the past 200 years, CO2 is responsible for most negative radiative forcing.
• D. In the past 100 years, the atmospheric lifetime of CO2 attributed to energy use increased.

Correct answer: A

Explanation

The correct answer is A because the increase in atmospheric CO2 with isotopes that match fossil fuel emissions directly links human activities to climate change. Options B, C, and D do not specifically attribute the changes in CO2 levels or their effects to human actions, making them less relevant for demonstrating human impact.