Former late-night talk show host and auto enthusiast Jay Leno is backing a California legislative proposal to allow an ...

Pollution and moisture also play roles. Urban smog often dulls the blue, creating a hazy or grayish appearance. On particularly humid days, water vapor scatters light in a way that softens the sky ...

Caption Two new concepts -- 'APEC Blue' and 'Beijing Smog' -- were coined in Chinese social media in November 2014 when Beijing hosted the APEC (Asia-Pacific Economic Cooperation) summit. To ...