Comment by shartshooter | Hacker News Reader

Comment by shartshooter | Hacker News Reader

Why do lawns even factor into the equation when the reality is that industry, farms, etc. own the majority of all water usage? I live in a desert area and hate seeing lawns watered in the middle of the summer but its impact seems trivial.

Agriculture is a major user of ground and surface water in the United States, accounting for approximately 80 percent of the Nation's consumptive water use and over 90 percent in many Western States.[0]

Households only make up a small percentage of the total water consumption worldwide[1].

Recommendations to cut foods that require an inordinate amount of water per calorie are probably better served(if you care about freshwater consumption) and it appears the simplest way to reduce this would be to cut out bovine meat.[2]

[0] - https://www.ers.usda.gov/topics/farm-practices-management/ir...

[1] - https://www.scientificamerican.com/article/water-in-water-ou...

[2] - https://waterfootprint.org/en/water-footprint/product-water-...

> ... would be to cut out bovine meat.

The somewhat ludicrous figure provided at that link - of 15,415 litres of water per kilogram of meat - is oft' cited by vegetarians and vegans, but doesn't bear scrutiny.

CAFOs are undeniably bad for everyone (the land, the animals, and the consumers) and while they doubtless skew the stats, those grossly artificial environments are clearly not locking up 15 tonnes of water per kilogram of meat.

Something closer to natural - say pastured raised cattle - are using much more reasonable volumes of water, especially at low stocking rates. But the whole 'using water' claim is muddied. The water the animal drinks passes through it and into the ground. Irrigation of the pasture, if performed, can't be thought of as 'lost' water either, as some will go underground, some will be lost as transpiration / evaporation, and some will be stored in the plant to then be consumed by the animal (qv).

> Why do lawns even factor into the equation when the reality is ...

Because lawns are, for most people, for most of the time, pointless wastes of land, water, pesticides, and energy. There are myriad (good) reasons to surrender some lawn and instead grow some of your own food -- TFA just pointed out one of the less obvious ones.

> But the whole 'using water' claim is muddied. The water the animal drinks passes through it and into the ground.

Yes, it's not like the water is destroyed. It may be diverted from directly flowing into a river, sure, and perhaps goes straight back to the atmosphere rather than into the sea via evaporation, exhalation, and transpiration... but it's not gone.

What the cow returns trashes streams as it’s high in nitrates. It’s incredibly damaging. New Zealand is a great example of this and the huge expansion of our dairy industry has done huge harm.

Only when the cow is allowed to go in the stream. Have the cow go even a few meters away from the stream and it is great fertilizer for the grass the cow eats.

Runoff still exists. That fertilizer (and honestly most commercial fertilizers) will still enter the stream and other water via rain.

Cows aren’t allowed in streams in NZ and this is mostly followed, with waterways fenced off. Our rivers are trashed.

I don't really see the point of this argument, isn't this true for basically _all_ water usage?

Exactly. Water is used, but not lost. Except for cases where more is drawn from an aquifer than replaces it (a very real problem, but not one that quantity of water used in beef touches in a useful way), the water is just passed on down the line. Thus the whole argument doesn't make sense. It is a big number that vegetarians like though because they can make it sound bad while the more complex truth is too complex to understand (and doesn't support their bias as well).

I find understanding this sort of thing is much easier to look at from an energy perspective than a materials perspective. Water is "used" when entropy is dumped into it that makes it less suitable for usage. It takes energy to turn it back into useful pure water. Nature provides a lot of energy that turns it back into pure water, but it may not do it as quickly as we use it, or where we want it, or when we want it. And sometimes the problem is that it dumps fresh water on us far in excess of our desires.

It's still not a perfect perspective, because the exact nature of what's in the water can be an issue (i.e., urine is "bad" for most uses, but may fertilize well, etc.). But it's at least closer to the truth than the mindset that water is poured into a cow and disappears from the universe entirely. If goodness and pureness was a one-time consumable item that way, the way some people seem to conceive of it, the ecosystem would have run out of it billions of years ago. It is a renewable resource.

Not really. If you put water on plants, most of it evaporates. Example: https://www.theguardian.com/sustainable-business/sustainable...

That still very much fits the 'it's not gone' definition.

Evaporated water will come down again as precipitation.

Your example (cotton) is a truly horrendous crop / textile, but that story sounds like a combination of very poor crop choices for the environment and spectacularly poor resource management.

Also, if you apply water at or beneath the ground/mulch layer, overnight, then your loss to evaporation is very low. Similarly, even suspended drip irrigation (think grapes or other trellis grown plants) versus mist or sprinkler systems.

Lawns, coming back to TFA, are almost exclusively irrigated by sprinklers, and because they're primarily residential (ie. no automated irrigation systems) they're often watered by hand during the day -- so incur a high evaporation loss.

Late edit: sorry DrRobinson, I lost track of the thread and wasn't really disagreeing with you.

>"But the whole 'using water' claim is muddied."

I agree, most of our water is technically "reused". However, one minor caveat is that if it goes down the drain then it most likely gets mixed-in with sewage and thus needs to be treated before being released. Which can definitely be some sort of resource burden.

Edit: Formatting.

It takes a lot of crops to feed animals, and those crops depend on enormous amounts of irrigation. The vast majority of agriculture exists for animal feed. I don’t know the exact source of that number, but I’d guess it included the water involved in growing those feed crops, not just what a cow drinks.

What number?

CAFOs are objectively horrendous things. Feeding grain to ruminants is also horrendous.

Using lots of fresh water, pesticides, herbicides, and fossil fuels to grow grain on high quality land -- rather than allowing grazing animals to graze on marginal lands -- is a highly dubious practice.

Nothing about that cycle is good for any of us, any of the animals involved, or the soil or water resource management.

What do you think the largest crop in the US is?

Hint: Turf grass.

Figure all the land used to grow lawns plus all the land used to grow grass seed plus all the land to grow sod... It's absolutely staggering amount of land, whole integer multiples of the land we use for corn or any other irrigated crop.

I couldn’t quite believe this so I looked it up: https://m.huffpost.com/us/entry/us_55d0dc06e4b07addcb43435d

Link to the actual paper, from 2005, is in the article.

Paper cited suggests 164K km^2 (about 40 million acres) of total turfgrass.

USDA estimate for corn crop in the US is almost 92 million acres.

Note that the paper claims that turfgrass is 3x larger than the largest irrigated crop, not that it's larger than all crops. Only about 20% of US corn is irrigated (~80% is rain watered only).

[1] - https://www.isprs.org/proceedings/XXXVI/8-W27/milesi.pdf

[2] - https://www.usda.gov/media/blog/2019/07/29/corn-americas-lar...

Lawns use far more fertilizer than agriculture per unit area. Many small suburban laws get as much chemicals as a farmer will put on many acres. The farmer is a businessman, excess fertilizer is wasted money off the bottom line, thus the farmer tries to apply only what is needed, and keep it on the field not run off into a stream (this is a very hard problem, I'm not claiming farmers are fully successful, but they make an effort and research shows they are doing okay). The suburban lawn gets excess chemical with no thought about will it run off.

Note that the suburban lawn does not need chemicals. If you want green colored lawn you need them. If you want green as in good for the environment a lawn without chemical input does fairly well, but it won't look as nice.

Regarding why lawns even factor, bear in mind TFA is from a media station and the advice to get rid of one’s lawn is likely targeted to people as a small tactical contribution to make.

When you get people to make small changes like this, they’re more likely to support big changes in polls and at the ballot box. That’s the lever by which one moves government and industry.

It doesn’t sound like the suggestion was made on the basis of water usage. Full quote FTA:

> “Get rid of your lawns,” she said. “Lawns are total biological deserts. It’s just grass with pesticides. The way it’s grown does not support a lot of biodiversity.”

It is not obvious to me why I'd want my front yard to be teeming with insects.

Because your world depends on them.

Get back to me when you can actually show that my world depends on a variety of insects contained within a single square mile.

Your world doesn’t see much change if you open a can of Freon on the front porch every day.

But if doing that was as pervasive as owning a lawn? You’d bet[1].

[1] https://www.epa.gov/ods-phaseout

Culture matters. You don't exist in a void. You, anyone you live with, anyone who sees your yard, and anyone who hears your views on it all carry a personal culture.

You are responsible for yours and who it infects. Is yours a sustainable one? If not, you're likely programming the world to die off.

It's not only about you. It's about the ripple effects of you and a greater understanding of responsibility in the face of culture as a force to reckon with.

The sum of everyone's yard is still insignificant to the issue. Bugs in yards aren't the bugs that might theoretically matter. You might note the perfect symmetry between the claims "you need a robust population of random bugs in front of your house" and "you need a robust population of random bugs inside of your house". Nobody needs either of those things.

Most of the world is in neither one of those places.

I've planted quite a few bee friendly plants in our garden - I find even the sound of bees to be utterly relaxing.

Sure, if you save water they'll just build a new golf course and someone else will use the water. But at least you don't have to pay for the water. You also get a more interesting yard that supports wildlife.

I would like to point out that getting rid of your lawn, using it to plant your own vegetables and eating them is a way to cut down on eating bovine meat.

"Why do lawns even factor into the equation... water usage?"

That's not what this article is about at all. But that's cool, I guess.

The article isn't even about water usage! It's about lawns being terrible habitats for insects...

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