Your Friend Insists That Any Changes in Atmospheric CO₂ Levels

question 112

Multiple Choice

Your friend insists that any changes in atmospheric CO₂ levels or global temperature are nothing to worry about. He claims that these are actually normal fluctuations that have occurred for thousands of years on Earth, and that human activities play no role in these processes. What evidence could you provide to counter this argument?

• A)An increase in global temperature can't be the result of normal processes such as volcanic eruptions, as these typically result in a drop in temperature.
• B)Isotopic carbon evidence (especially atmospheric levels of ¹³C)demonstrates that human processes are in fact contributing to atmospheric CO₂ levels.
• C)Current global temperature changes are occurring much faster than would happen under normal circumstances.
• D)All of these choices are correct.

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Definitions:

Signal-Detection Theory

The theory that perceiving or not perceiving a stimulus is actually a judgment about whether a momentary sensory experience is due to background noise alone or to the background noise plus a signal.

Classical Psychophysical

Relates to the traditional study of the relationships between physical stimuli and the sensations and perceptions they produce.

Sensitivity

The capacity to perceive, feel, or be aware of stimuli or changes in the environment; can also refer to the degree of responsiveness to social or emotional matters.

Weber Fraction

A principle that quantifies the perception of change in a given stimulus, stating that the just noticeable difference is a constant proportion of the original stimulus’s intensity.