1.   Cleaning up city air is also easier than curbing output of carbon dioxide, a gas thought to cause climate change.

2.   Higher temperatures in New York, a result of the urban heat-island effect, likely prevented city air from ever reaching its saturation point.

3.   I like the city air.

4.   In addition, he said, luna moths seem to manage in grimy city air.

5.   Indeed, there are times when rooftop amenities seem to appear out of thin city air.

6.   They strip filters of the filth borne by city air, dirt so thick it forms a three-inch carpet that could make any unit go blooey.

7.   Country folks with urban roots, like the Brooklyn-native Zachai, depend on it for a breath of gritty city air.