Yeah, we're ancient lake bottom. The only rocks i can find on my property were brought in.

That would be pretty cool, provided they didn't become crazy invasive.

From my livingroom window, i can see a few thousand trees. Probably 75% of them are Russian Olive trees, which stink and have large spines that will punch through a leather glove.

I do not live in Russia. These were brought in a few decades ago and planted as decoration. They're EVERYWHERE now.

And they're kinda dangerous. They get to 30-35' tall, then just randomly fall over.

That's not what I'm referring to. Trees and brush in the median. Think Tuscon AZ, not Beverly Hills.

If you're coming from europe, i can understand how it's hard to wrap your head around the type of land in the western US, because there's isn't really the same type of thing anywhere in Europe to my knowledge.

Just the Bureau of Land Management handles around the area of one tenth of all of Europe (around 1 million km²). That's public land, no one lives on it. Almost all of it is used as grazing land to some extent. It's not really used otherwise except for recreation. That doesn't include national parks and national forests which are also commonly grazed in part. It doesn't include huge ranches that aren't factory farms. It doesn't include small farms and landowners that rent out fallow fields to cattle ranchers.

And the yield of that land is extremely variable. My 3.4 acres are listed among the highest potential yield crop land I've seen at well over 100 bushels per acre of most common crops. 10 miles north of me there's rolling hills of pasture land that probably could yield 25-40 bushels per acre if you could farm it. 100 miles southwest of me, your crops are probably just going to fail, but cows can scratch together enough food to gain weight for 11 months of the year.

So, factory farms put feed lots on land like that to the southwest of me and then buy feed from my neighbors here in the extremely fertile area. They can actually have 100 cows per acre. The ranchers to the north of me are probably running 1 cow per acre. Any ranchers to the southwest doing grazing are probably more like 5 acres per cow.

The factory farm needs crop land, and i can't find the actual calories per acre for just grass hay, but wheat is significantly more calorically dense and that's around 6.4 million Calories per acre. Corn is 12+ million, and that's for human consumption, but cows eat the stalks, too. So, i think a reasonable estimate would say a feed crop produces perhaps 3x the calories per acre of grassland on the low end and upwards of 10x at the top end.

So, ranching cows on pretty decent grassland is 1 acre per cow. Factory farming requires 0.11-0.31 acres per cow (0.1-0.3 acres for feed, 0.01 acres for pen space, plus a tiny bit for waste control). And the worse the land yield is the more acres you need. Factory farms exist for a reason: they're cheap and efficient.

But ALL that land is weighted the same in your narrative. It isn't the same at all. Factory farms and cropland is essentially worthless to wild animals. Rangeland is some animals primary habitat.

Monoculture crops can actually be much more damaging to the environment than rangeland raised meat, even when you account for the area required per calorie.

Without a doubt, but if you know a danger, you can probably buy a part of a cow.

Oh, and as for your tangent, it's easier to know what you're eating if you can get a ways out of the city. Most of our eggs come from our chickens, we can easily get beef and pork from people that we know and can go see the animals in the fields. Hell, i can get the ear tag of the cow i put in my freezer if i want.

I'm not making that mistake at all. I'll pointing out that a huge percent of the Western US is considered "used for cows", even though there's only a few cows per square mile, and the cow's use of that land is pretty low impact.

If you lump that in with factory farms where even considering the area required for feed, you're getting multiple cows per acre, you end up with a drastically skewed statistic where the average land use per cow is very different from the median land use per cow.

And since the vast majority of our meat comes from factory farms (I'm seeing 99%, but that's not just beef), the median land use is far more important. So, if you include the few hundred thousand square miles of rangeland with barely any cows on it, you think every cow we don't raise frees up like 4.6 acres that can go towards something else. But in reality, if we don't raise one median cow it only frees up a couple hundred square feet.

Do you see how the statistic is skewed? I've been around feed lots and live in agricultural areas. I see feed crops. I also live near rangeland. A simple statistic of "percentage of human land use" doesn't really tell any of that story with any degree of accuracy.

True, birds and bugs would absolutely love it.

One ironic addition to this is another common issue is people often don't dig a big enough hole. They dig a small hole and put the tree as deep in it as they can. In truth, you want a big hole that can allow the roots to spread out the same way they naturally grow, but still have the boundary of the root/tree at the surface of the ground.

My parents, who have planted enough trees on their 40 acres, that it has affected their microclimate significantly, say if you buy a $10 sapling, dig a $100 hole. It needs to be both deep and wide. And if you have hardpan, you need to break through it.

I think you're making an error in the implied assumption that the aforementioned land is all equal. It isn't. For example, there's a county of roughly 10000 square miles in southeastern oregon that has arouns 7000 people in it. It's got a little bit of protected area, but the VAST majority of it is cattle rangeland interspersed with hay/alfalfa fields. There's occasionally other crops, but not much. There's a lot of meat coming out of that country, but it's not dense. Every cow needs a massive amount of space to graze enough to slaughter, but that's because there's just not much out there. There's not enough water to sustainably grow food crops, but a cow can wander a few miles a day munching on bunch grasses and be fat and happy.

Additionally, a lot of rangeland is far closer to wild than farmland. Cattle are grazed on huge swaths of BLM land in the western US, that is essentially just wild land. To convert even 20% of that to any other use would be a massive ecological disaster. And the cows do some damage, too, but nothing like clearing forest and planting crops.

This use would DRASTICALLY affect any such statistics like the one you're quoting. Meat production on factory farms fed by monoculture feed crop field have their own problems, but they are far more space efficient than the story your numbers paint.

The intensive ones are awesome to see, but not practical. Thd extensive ones won't have near the impact on local temperature of trees.

The problem with green roofs is cost and potential failure. It's actually very difficult to seal them, and when a leak does show up, it's difficult to fix. Trees tend to also be absolutely excellent at breaking through even concrete, so planting trees on roofs is asking for a problem.

Green medians can be a much more cost effective way to green up a city. Small rooftop gardens with potted plants or shallow beds with shallow rooted plants could help.

I would love to see 80' tall sycamores and maples on top of skyscrapers, but i don't think it's practical.

I certainly wouldn't plan on buying tickets on such a plane any time soon.

I'm no expert on hydrogen containers, but i do believe some of our better options emply ceramic coatings, but they can't generally be pure ceramic, because they can't handle the hoop stress. Also, i think most ceramics still leak a significant amount of hydrogen.

I mean, you could be right, but with the lifetimes we're demanding of aircraft, i think it would behoove us to keep everything from hydrogen embrittlement. Injectors might be the main trouble spot, though.

I was also thinking of much larger lifting bodies, like flying wings. I don't think you'd need to rebuild airports completely, but renovations would for sure be needed. But in that change, you could get some significant benefits, like higher altitude flights with greater ease.

But i disagree with your claim of reusing things rather than building new. For most things like cars, the carbon use of the fuel or energy quickly outstrips the corbon footprint of production. So, continuing to use that refrigerator from 1956 that keeps on chugging is churning out more carbon every few years than building a new fridge. Replacing a car that gets 20 mpg with a new one that gets 30-35 mpg has a very rapid "carbon payback".

If efficiency is more or less constant, sure, keep using the old thing as long as possible. If new versions produce significant improvements, replacement is the best option. The math for these decisions isn't that complex.

Gold might not be a bad material for it, especially on tubes and engine parts, but I don't know enough about gold playing to know if it's adherence is good enough in a thin film application to coat something like a turbine.

Another problem is hydrogen's flame temp is absolutely insanely hot. Gold has a fairly high melting temp for such a soft metal, but it will need excellent cooling. It's conductivity could help a bunch with that though.

Damn, i wish i was in engine r&d sometimes. All my fiddling with engines is on 4-bangers in my shop. And i don't even have a cnc.

We have materials that can hold hydrogen well, and it's trivially easy to make an effectively impermeable coating on something like a compressed gas cylinder. But doing the same for a full plane is less simple.

And we have some promising materials for that, like some graphene based stuff. It's not as far out as you suggest. It's just a long way from cheap.

For airplanes, the energy intensive nature of it doesn't matter quite so much. We can produce it on the ground using alternatives, but up in the air is where energy density matters, both per unit volume and mass. Hydrogen has mass energy density in spades, which does matter.

There's definitely some barriers, but if we can get it to work, it opens some massive doors for fighting climate change.

It's possible, even likely, that an algae based biofuel could be a lower hanging fruit, but before that gets to be carbon neutral, it has to scale to support the full supply chain. Hydrogen doesn't have that limit. We could produce it cleanly, even with non-firm power options like solar and wind. Then from day one, it's carbon neutral.

Not to mention nearly all metals and some other materials suffer "hydrogen embrittlement" which causes them to fail catastrophically after extended exposure.

Hopefully it works out, but there are still significant engineering challenges to overcome before this is commonplace.

That's also not correct. It can sleet or snow significantly above 0⁰C. Hail pretty much ONLY occurs well above 0⁰C. The coldest day I've seen hail on was in the high 30s F, the warmest I've seen it was around 80⁰F.

In dry air, pooled water can start freezing around 40⁰F fairly easily. In REALLY dry air, drops can freeze way above that.

It depends on relative humidity as well as dry bulb temp.

Edit: is actually dropping a mixture of rain, sleet, and hail outside my window right now at 39⁰F.

None within many miles of me. It's all feed corn or alfalfa here, and most of it is lease-farmed, so the landowners don't store it.

That's not that bad. I was consistently 700+.

The other internet i had couldn't even do Netflix. This one does better. If starlink was decent latency, i could possibly be convinced to switch.

I saw it's in open trial here, but what type of latency does it have? I do work from home, so i need internet.