B. Phoenix is also the largest city in Arizona and the fifth most populous city in the United States. Its Sky Harbor airport has longer runways to help accommodate flights on hot days. Hot air is less dense which means less air flowing over the wings for lifting the aircraft and less air flowing into the jet engines.

Q: It reached 119 degrees in Phoenix last Tuesday and 124 degrees in the hottest spot in the nation. What state has recorded the highest temperature?

A. Arizona

B. California

C. Nevada

D. Utah

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B. Death Valley in southeastern California is one of the hottest places in the world at the height of summertime. It holds the record for the highest reliably recorded air temperature in the world, 134 degrees on July 10, 1913. But, this record has been contested by some weather experts.

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Q: A new study finds that 30 percent of the world’s people are exposed to potentially deadly heat for 20 days per year or more. Researchers cited a 2003 heat wave that killed approximately 70,000 people in . . .

A. Africa

B. Asia

C. Europe

D. South America

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C. The summer of 2003 was the hottest on record in Europe since at least 1540. In the study, scientists said climate change could put 75 percent of the world’s population at risk of killer heat waves by 2100.

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Q: Climate change also has been tied to more intense jet stream winds high altitudes that are making flights bumpier as well as creating stronger headwinds or tailwinds for high-flying jets. The jet stream SPEEDS up U.S. flights heading which direction?

A. East

B. West

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A. The jet stream flows west to east around the northern hemisphere. So, planes flying east would get a boost from tailwinds. But, planes heading west are slowed down and use up more fuel.

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