How Do We Know Whether or Not Global Warming Is

question 83

Multiple Choice

How do we know whether or not global warming is caused by humans?

• A) From experiments in which a small experimental plot of forest is subjected to excess carbon, and the growth of the trees along with the temperature are then measured.
• B) From computer calculations that "predict" 20th- century temperatures, based on natural variations, then on human- caused variations, and then on a mix of natural and human variations; the actual historical measurements then show the importance of human variations.
• C) From experiments in which excess carbon is injected into a laboratory- created Earth- like atmosphere, and the resulting temperature is measured.
• D) From computer calculations that "predict" 20th- century temperatures based on natural variations, then on human- caused variations, and then on a mix of natural and human variations; the actual historical measurements then show that only natural variations are important.
• E) Actually, scientists have been unable to determine this.

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Definitions:

Sleep

A naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity, and inhibition of nearly all voluntary muscles during rapid eye movement (REM) sleep phases.

Aging

The process of becoming older, which includes biological, emotional, intellectual, and social changes.

Hypothalamus

A region of the brain that regulates basic biological needs and motivational systems such as hunger, thirst, and body temperature.

Sleep

A natural condition that impacts both mind and body, marked by a change in consciousness, reduced sensory experiences, and a suppression of most voluntary muscle movements.