Grass

Lawns - long known to be the main culprit in urban water consumption, now can be blamed for another environmental woe - greenhouse gas producer in excess of whatever carbon it 'sinks'. The gas is nitrous oxide - 300 times more potent than CO2.

Water saver or environmental hazard? Questions are compounding about artificial turf as more homeowners ditch their grass for fake lawns. Contradicting city policies muddy the issue in the arid Southwest.

When mandatory water conservation rules took effect in Glendale, California, homeowner David Wood installed artificial turf to maintain the green front yard emblematic of the American Dream. But his new fake lawn is against the law.

Cities in the Southwest are drying up. With less water to go around, water-intensive plantings like vast lawns are becoming an environmental faux pas. Now some cities are compensating residents for getting rid of them.