Methane is colorless and odorless, too (the smell of natural gas fuel is artificially added as a safety measure). If you strike gas underground, you’re going to notice it, and pockets of hydrogen would show up in the same ways that we’ve been using for longer than I’ve been alive to detect pockets of methane.
Maybe. The oil and gas industry is the product of a century of development that has spanned the days of trivially recovered oil, where all you did was drill a short distance down and it would gush up - to the modern world where all the easy oil is gone and wells can cost 100 million apiece. But all the time, we saw incremental improvements in discovery and production fuelled by an insatiable demand and almost incomprehensibly huge money.
The price for recovery of oil varies dramatically. The Saudis can make money with an oil price as low as $25 bbl. As we saw recently, Venezuela was unable to make money at $120. Most other producers sit somewhere in the middle. Fracking is another modern technology that is very cost sensitive. It fades in and out of economic viability.
So it depends a great deal on what you call “as easy to harvest”. In the modern world no oil or gas is easy. That has all long gone.
Geological hydrogen, as described, doesn’t fit the usual model for oil or gas. The source mechanism is totally different. It does have in common the need for some form of seal. so some exploration techniques and understanding will overlap. But as a good approximation, nobody will have been looking for hydrogen and even if they surveyed an area with any reserves they may well have simply ignored whatever geological curiosity they displayed. Petroleum and gas tends has strict requirements in terms of source. Geologists won’t be drilling into anything until they have a very clear idea that there is a good seal, and a good geological history that fits with the creation of oil or gas. One thing you don’t want is to discover is that your hydrocarbon deposits are overcooked and basically coal. There is a lot of coal down there. But it won’t flow up a pipe. Geologists look for regions that have known influxes of suitable biological material (despite what popular science says, mostly algae), and a period cooking at the right temperatures. The bar is set very high before anyone pays for an exploratory well. The eye watering costs result in very conservative choices. There is some poor exploration geologist who makes the call on where to drill. If he misses, he blows many millions of his companies money, and probably needs to get his CV up to date.
Economically interesting hydrogen, if it exists is likely reasonably deep. It will need to be under a good seal. Salt is a good one. Volcanic flows are another. Sedimentary rocks are not. It needs water and iron and heat. These are not uncommon at depth. It mostly isn’t going to be found in places we are drilling or mining for other things. Different geological process make for different targets.
The huge win for oil is the easy transport, high energy density and a century of demand that has built an extraordinary amount of infrastructure. Natural gas has only recently hit similar levels with the advent of large scale liquefaction. Again, a technological advance involving staggering costs. Here in Australia the Gorgon LNG plant cost 55 billion USD. That doesn’t include the production wells.
Whether there are economic reserves of hydrogen about is one question. But the demand for energy can result in extraordinary investment. That said, the problems with hydrogen are so large that the way in which it is used would need to be very different to the current models. As a raw energy commodity it is really not good. But there is some low hanging fruit. As a feedstock for fertiliser is perhaps the top one. Make ammonia as close to the well head as you can. That could account for 1.4% of current global CO2 emission alone, just making fertiliser. Fed into steel production is another clear winner - but has the real problem of transport. Transported as ammonia, it might be viable. I suspect large tankers filled with liquid ammonia would give a lot of people the willies, but it is a less demanding cargo than LNG, and we ship vast quantities of that about.
As a fuel for ICE powered cars hydrogen is a non-starter. Toyota seem to have a death wish in their headstrong attitude. I don’t care how fabulous an engine they can design to burn hydrogen, if they really believe in it they need to come up with solutions for transport and distribution. And there few to no viable solutions apparent.
No, we are not going to be saved by natural hydrogen. But I would not be dismissing it out of hand either. It may actually have an economically useful part to play. I just doubt it is a big one.
I understand the difference between “forcing” and “feedback”, thank you, and it is specifically the emissions that continuous emission of vapor in the upper troposphere and stratosphere that increases heat retention despite the fact that excess water vapor does precipitate out on a timescale of days, a point that would have been clear if you’d quoted my entire sentence instead of your careful editing to remove that qualification:
Next time, please do me the basic courtesy of quoting my entire sentence for context instead of ‘creatively’ truncating to so that you can dispute the ‘point’ that you want it to seem I made instead of what I actually wrote.
Stranger
What percentage continuous impact on global heating do you consider “substantial”?
I’m sorry, I’m unable to even parse that statement. The fact is that (a) the relative humidity of the atmosphere is maintained in a fairly constant balance dependent only on temperature, and that (b) the absolute humidity increases as the air temperature increases.
Water vapor is a very important consideration in radiative transfer computations in climate models, but its relevance is strictly as a feedback. Your statement that it’s “a potent if not persistent greenhouse gas” is just hugely misleading. Show me where in any IPCC graphs of greenhouse gas radiative forcings water vapor is even mentioned.
I will never suggest putting H in cars, not even fuel cell vehicles, such as the Toyota Mirai. It’s better to convert the hydrogen to electricity and put that into cars. Which is why I suggested putting a hydrogen-fueled power plant next to a large hydrogen deposit. It’s a lot easier to transport electrons than hydrogen molecules. Now whether there’s a large enough H deposit somewhere in the world is the $64B dollar question.
I literally just asked you to quote the entire sentence. Stop quoting partial sentences, or better yet, just stop fucking stalking and ‘selectively’ quoting me at all.
Stranger
I’m on my phone so this’ll be terse.
There is significant evidence tbat contrails are a net greenhouse phenomenon. In the daytime they’re slighy cooling but at night they’re strongly warming. Lots of long haul flying happens at night.
Research on mitigations is ongoing.
Hydrogen powered jetliners would supercharge the warming side of that equation.
OK. With all respect, let me try to clarify a potential misunderstanding. Here is your entire sentence:
And here is the crux of my response to that:
Again, show me where emissions of water vapor in itself is cited as a factor that exacerbates global warming, where it’s a net forcing and not just a feedback.
The reason you see the same people quoted in the OP’s link and every single other article on this topic is that they really like talking about geologic hydrogen to anyone and everyone.
Magic words in DC: “We’re setting funding priorities and hear you have some opinions on this topic . . .”
Wouldn’t that be: “how many votes can you bring to the table?”
Don’t get me started on solid fuel boosters for human spaceflight…
OK, I know that’s totally off topic and I won’t continue it here, though it continues to amaze me.
Sorry; I’m realizing people can’t see the context in my head if I don’t write it. No. I don’t talk to congress and most of these folks don’t either (their bosses might.) Multiple funding agencies and private organizations are trying to figure out what, if anything, to do here, so there have been a lot of meetings. A lot of emails. And a lot of hijacked happy hours.
Interesting comment about contrails. Contrails seem similar to cirrus clouds and indeed in high-moisture conditions can turn into them. Clouds are a complicated and contentious phenomenon in climate studies; broadly speaking, low-altitude clouds have an overall cooling effect on the regional climate by blocking solar insolation, while high-altitude icy cirrus clouds tend to contribute to warming by predominantly reflecting back thermal radiation from the surface. The effect of clouds on climate change is still the subject of controversy and further study but so far there’s no evidence that either the warming or cooling effects are going to dominate or otherwise be significant.
Below is an interesting article about liquid hydrogen in aviation. A quick one-sentence summary is that the effect on climate is largely dependent on how the hydrogen is produced, not on the consequences of burning it. I should stress here that my argument with Stranger above is not to be argumentative but to highlight an important fact: the fact that burning LH2 produces water vapor has no appreciable impact on climate, whereas burning fossil fuels that produce CO2, which is a long-lived greenhouse gas, will impact the climate directly for hundreds of years and likely thousands of years more from follow-on feedbacks.
From a financial, not climate science, perspective there’s considerable skepticism by the investment banks, etc., that the capital investment could be marshalled on anything near the requisite scale and timeline to bring either SAF or hydrogen into being as an aviation fuel.
In the view of several McKinsey-like outfits I’ve read, the whole thing is little more than a cynical game to suck up subsidy cash and seed funding. It can’t possibly work as a business.
I’m not in a position to meaningfully score that contention, but Wall Street types have a habit of being right, often by leaning on the scale until they make themselves right.
I’ll belive that a contrail may have a net warming effect, but how significant is this in the overall picture? What percentage of the earth’s surface is actually covered by contrails at any given time?
Also, would using hydrogen as jet fuel make contrails much worse than they are now? Not that hydrogen is a good jet fuel candidate for all the reasons we’ve already covered.
I’m prepared to be proved wrong by actual quantitative evidence, but my intuitive sense is that contrails are a drop in the bucket, lost in the noise.
Completely off topic, but there is a wonderful mosaic mural in Torcello cathedral on an island in the Venice lagoon which depicts souls being weighed at the last judgement. And the devils are sneakily tipping the scales… 
There were studies done using data from immediately after 9/11, when all flights were grounded. They generally find an increase in daytime temperature, because contrails can block incoming radiation, but a decrease in nighttime temperatures, because contrails also block heat from radiating away.
The conclusion was that this was a net warming effect, and was pretty significant. It was large enough that some scientists suggested planes fly at lower altitudes, even when taking into account additional fuel use, because contrail formation is less pronounced at lower altitudes. 24,000 feet instead of 35,000 feet, for example.
It’s also my understanding that it isn’t only the contrail itself that causes the problem, but the contrail can lead to additional cloud formation, possibly by providing nucleation sites for ice crystals to form.
This is the first search result I found, and seems to be a reasonable and brief summary. I do not know if newer science has come out refuting these findings, or even how controversial they are.
I’m sure that reduced flights may have reduced warming effects.
But was this really much to do with contrails? I doubt it.
As I said, how much of the earth’s surface is covered by contrails on average at any given time?
And how many of these are obscured by existing clouds?
Actually this is a rather interesting Fermi question:
We can approach it by using data about how many miles are flown by airplanes every day, how wide the trails are, and how long they last.
Appeal to authority. That is what the scientists who wrote those articles think, and in the articles they present their reasons for thinking that. The temperature change they were looking at were on 9/12-9/14 or so, not some future difference, but the direct change caused by removing contrails for a few days. They do various comparisons to historical data, and look at changes in places that usually have lots of contrails compared to places that only have a few.
The issue is that the aviation industry has committed to net zero. Which means zero from all sources, not just from burning carbon. Once it was discovered that contrails are an issue, they need to mitigated too.
The fact lots of contrails are spread in the high latitude and polar regions which are already hyper-sensitive to climate forcing, makes the issue more potent.
Yes, air transport is just a couple percent of total human greenhouse forcing. And contrails are just a couple percent of that couple percent. But they’re very politically vulnerable percents. And they might be something that’s rather cheaper to address than replacing the fuel supply infrastructure. Low hanging fruit and all that.
Here’s a couple of abstracts to get you started: