In parts of Northern California, background ozone levels already account for more than three-quarters of total ozone, leaving little room for local ozone production if stricter standards go into effect. (Flickr user Lisa Brettschneider, CC BY-NC 2.0)
Home In parts of Northern California, background ozone levels already account for more than three-quarters of total ozone, leaving little room for local ozone production if stricter standards go into effect. (Flickr user Lisa Brettschneider, CC BY-NC 2.0) In parts of Northern California, background ozone levels already account for more than three-quarters of total ozone, leaving little room for local ozone production if stricter standards go into effect. (Flickr user Lisa Brettschneider, CC BY-NC 2.0)
In parts of Northern California, background ozone levels already account for more than three-quarters of total ozone, leaving little room for local ozone production if stricter standards go into effect. (Flickr user Lisa Brettschneider, CC BY-NC 2.0)
