http://www.sciencedaily.com/releases/2010/01/100119133515.htm

The study doesn't say what practices the city was using but organic fertilizers don't use chemicals in production and it would be interesting to know how water deeply and infrequently and mow high (and less often) would compare to the carbon foot print found in the study. Additionally, I wonder how many of us would give up string trimmers and gas blowers to keep our grass?

This sounds like propaganda from the "no lawns" squad. Sure nitrous oxide is a problem but lawns are not a factor worth considering. Every time a gasoline or diesel motor runs it is compressing and oxidizing nitrogen from the atmosphere. When air (78% nitrogen) explodes inside a motor cylinder, it shoots back to the atmosphere as oxides of nitrogen. If you have a 4 liter motor, every revolution expels 2 liters (roughly a half gallon) of oxides of nitrogen (4-cycle engines only burn fuel/air with every other revolution). If it runs at 1,800 RPM for 40 minutes a day, that's 144,000 liters or 38,040 gallons of oxides of nitrogen. How much does a lawn produce?

Internal combustion engines are the problem for nitrogen, not lawns. Turbine engines operate at very high pressures and burn nitrogen, too, so they are not an answer. External combustion does not produce anything like the same amount of nitrous oxides as internal combustion. You still carbon fuel to get power, but you don't burn nitrogen along with it. Steam engines are external combustion engines. You don't have to make water steam. There are lots of other gasses and liquids.

I think I watered my lawn 4 times last year. Considering where I live, that means that my lawn had about 4 inches of water total.

I mowed 4 times, too, but that was because I wanted to mow the leaves into the lawn.

I haven't fertilized with anything but UCG for at least 5 years and haven't fertilized at all for 2 years.

I don't think that article is about me.

The thing I think you really show is there are ways to have lawns without the high maintenance that may contribute to climate problems (may). I use organics except for the last feeding in the fall and water less frequently and higher and mulch mow, but, I confess, I use a lot more irrigation than you do. (Fescue and bluegrass fwiw).

But I'm willing to bet that you use half as much water as your neighbors do. Or less.

I really got started on this whole thing when my city gave us the option of installing unmetered water for irrigation. Somebody came around with a petition and told me it would pay for itself in two years (which meant that they were paying more than $800 to water their lawn). I did the math and figured it would take more than 20 years just to get the water to my property (not even counting the loss of earning power of the money during that time). And I'd still have to pay a plumber to hook it up (if I wanted to do it legally and safely since doing it wrong would mean introducing untreated water into the drinking water).

So the following year, when the city saw how much the water revenue dropped, they raised the water overage and dropped the threshold when they started to charge it.

The lawn I've got now would probably live with no additional water, but I'll need to continue watering it once or twice a month during the summer to keep it green.