Hey, EPA, Why Not Regulate Water Vapor Emissions While You are At It?

From Dr. Roy Spencer’s Global Warming Blog

by Roy W. Spencer, Ph. D.

Some Background

I will admit that the legal profession mystifies me. Every time I say anything related to environmental law, one or more lawyers will correct me. But I suppose “turnabout is fair play”, since I will usually correct any lawyers about their details describing climate change science.

Lawyers aren’t like us normal people. Their brains work differently. I first suspected this when one of my daughters took the LSAT and gave me examples of questions, most of which my brain was not wired to answer correctly. I became further convinced of this when she went to law school, and told me about the questions they deal with, how lawyers can impress judges just by being novel in their arguments, etc.

I know I could never be a lawyer (even after staying at a Holiday Inn Express), and I never even played one on TV. But I did co-author a paper in Energy Law Journal (relating to the Daubert Standard) on my view that science cannot demonstrate causation in any rigorous way in the theory of human-caused climate change.

Regulating CO2: Is the EPA Really Trying to Help Us?

The regulation of CO2 emissions (and some other chemicals) by the EPA has also mystified me. However many of the EPA’s ~185 lawyers worked on the 2009 Endangerment Finding, they must have known that regulating CO2 emissions from U.S. cars and light-duty trucks would have no measurable impact on global climate, including sea level rise (which was a major argument in Massachusetts v. EPA).

None.

But apparently actually trying to “fix” the climate “problem” is not the EPA’s concern.

Their reason for existence is to regulate pollutants (and it doesn’t matter if Nature produces far more of a “pollutant” than people produce). And once they start regulating it, they won’t stop with certain thresholds. They will keep lowering the threshold. This keeps everyone in jobs.

I know this is the case. I once attended a meeting of the Carolinas Air Pollution Control Association (CAPCA), and the keynote speaker (from the EPA) stated, “we can’t stop making things cleaner and cleaner”. There was a collective look of astonishment in the audience, which was primarily industry representatives who try to keep their companies in compliance with state and federal environmental regulations. I assumed their real-world experience told them it is impossible to make everything 100% clean (what would it cost to keep your home 100% clean?).

And we wouldn’t want to anyway because (as Ed Calabrese has explained in many published papers), it is necessary for resilience in biological systems to be exposed to stressors. I almost never get sick, which I attribute to a pretty filthy childhood of playing in heavily bacteria-contaminated waters, not washing my hands, etc. I was sick a lot then. But not later in life. This is why the EPA’s reliance on the “linear no threshold” assumption (simply put, if a gallon of something can kill you, then one molecule is also dangerous) has little to do with our real-world experience and common sense. Kind of like the legal profession.

So, is the EPA really trying to help us? I increasingly believe they are not. They are trying to keep their jobs (and grow even more jobs; coming from NASA, I know how that works). The law (and regulations) are tools to accomplish that. Yes, the EPA has accomplished needed pollution controls through the Clean Air Act. I’m old enough to remember driving through Gary, Indiana in the 1960s, trash lining the highways everywhere, waterways choked with pollution and even catching fire.

But at what point does the Government say, “OK, we fixed the problem. Good enough. Let’s not throw the baby out with the bathwater with damaging over-regulation.” No, that doesn’t happen. Because of the perverse way in which environmental regulations are written.

So, EPA, What About Regulating Water Vapor Emissions?

The EPA regulating CO2 emissions has a few problems, which seem to have not stopped the legal profession from doing what they do best. As I mentioned above, U.S. CO2 emissions from cars and light-duty trucks will have no measurable impact on global temperatures or sea level rise.. You could get rid of them completely. No measurable effect, Yet, here we are… regulating.

Since these are “global” problems, it has long been known that the EPA (and maybe even the Supreme Court’s Massachusetts v. EPA decision) could be on shaky ground, and maybe these are matters better left to legislation by the U.S. Congress.

But what about water vapor emissions from such vehicles? Now, there is a real possibility! Burning of any fuel (especially if we have hydrogen-powered vehicles) produces water vapor. And on a local basis (in your town or city) this extra water vapor will increase the heat index in the summer. And, and as everyone knows, “it’s not the heat, it’s the humidity”.

That’s a local problem caused by local sources of pollution, and seems to be much better suited for regulation by the EPA, which is a U.S. agency, dealing with U.S. pollution concerns.

The climate scientists who publish papers about the supposed dangers of greenhouse gas emissions make sure to exclude water vapor from their concerns, claiming CO2 is the thermostat that controls climate. I have commented extensively on the sleight of hand before. The vast majority of climate scientists believe CO2 controls temperature, and then temperature controls water vapor. CO2 is the forcing, water vapor is the feedback. But this argument (as I have addressed for many years) is just circular reasoning. The amount of water vapor in the atmosphere (did I forget to mention it’s our main greenhouse gas?) is partially controlled by precipitation processes we don’t even understand yet. The climate modelers simply tune their models to remove water vapor (through precipitation processes) in an arbitrary and controlled way that has no basis in the underlying physics, which are not yet well understood. Often, these simplifying assumptions translate into assuming relative humidity always remains constant.

But I digress. What I’m talking about here isn’t regulating water vapor emissions for global climate concerns… it’s to reduce their impact on summertime heat, especially in cities.

But why stop at vehicle emissions? Humans exhale lots of water vapor (joggers even more!). Maybe we should limit jogging and the sale of bottled water? Not a big enough problem, you say? Or maybe that’s an FDA thing? I don’t know… I’m just a simple country climate scientist.

As attorney Jonathan Adler commented in response to my recent blog post on the Endangerment Finding,

The problem is, the concerns you raise are not relevant in making an endangerment finding under the Clean Air Act. The textual standard is precautionary and does not allow for any cost-benefit balancing or consideration of other trade offs. All that is required is that the EPA administrator can reasonably anticipate some threats from warming to health or welfare, the latter of which is defined quite broadly.

So, we are back to the regulatory fact that if a “pollutant” (whatever that means) causes any level of threat, discomfort, worry, anxiety, then the EPA is compelled to regulate it. How convenient. Well, I would argue water vapor emissions, especially in the summer in cities, are better suited to regulation under the Clean Air Act than CO2 emissions are.

So Why Hasn’t Water Vapor Been Regulated?

Clearly it’s not because water vapor is “necessary” to the functioning of the Earth system, since CO2 is necessary for life on Earth to exist. Which brings me back to my question, is the EPA really trying to help us when it comes to climate-related regulation?

I’m increasingly convinced that science has been hijacked in an effort to (among other motives) shake down the energy industry. This has been planned since the 1980s. It makes no difference that human flourishing depends upon energy sources which are abundant and affordable. It doesn’t matter how many people are killed in the process of Saving the Earth. The law demands regulation, and that’s all that matters.

I have evidence. In the early 1990s I was at the White House visiting Al Gore’s environmental advisor, Bob Watson, a ex-NASA stratospheric chemist who was just coming off the successful establishment of the Montreal Protocol on Substances that Deplete the Ozone Layer. He told me (as close as I can recall), “We succeeded in regulating ozone-depleting chemicals, and carbon dioxide is next“.

Keep in mind this was in the early days of the IPCC, which was tasked to determine whether humans were changing the climate with greenhouse gas emissions. Their work was just getting started, including the scientists who would assist the process. But the regulatory goal had (wink, wink, nod, nod) already been established.

So, I don’t believe the EPA is actually trying to help Americans when it comes to climate regulation. I’m sure many of their programs (waste cleanup, helping with the Flint, MI water problem, and some others) are laudable and defensible.

But when it comes to regulation related to global climate (or even local climate, as the government tries to pack even more people into small spaces, e.g. with “15 minute cities“), my experience increasingly tells me no one in the political, policy, regulatory, legal, or environmental advocacy, side of this business really cares about the global climate. Otherwise, they would admit their regulation (unlike, say, regulating the precursors to ground-level ozone pollution in cities) will have no measurable impact. They wouldn’t be trying to pack people into urban environments which we know are 5-10 deg. F hotter than their rural surroundings.

It’s all just an excuse for more power and vested interests.

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March 4, 2025 4:45 pm

Average annual rainfall is about 1000 mm. Average global water vapor is about 29.8 kg/m^2 (= 29.8 mm). All rainfall came from WV so the atmosphere has to be ‘refilled’ 1000/29.8 = 33.6 times. The average residence time is the reciprocal of this = 0.0298 year = 10.877 days.
Further analysis shows that the part of WV increase attributable to humanity can account for all of the climate change attributable to humanity. https://watervaporandwarming.blogspot.com

TPW-UAH-6.1.5
March 4, 2025 4:49 pm

About 90 % of the human contribution to water vapor is from crop irrigation.

Reply to  Dan Pangburn
March 4, 2025 6:29 pm

Most irrigation water is pumped from deep aquifers, bringing it back to the surface and into the atmosphere. It was formerly sequestered, where it was obtained by mining as a pulse in time. There is therefore no question as whether it is a greenhouse gas liberated by humans.

Seems to fit the regulatory reasons we have now for preventing climate change, now doesn’t it?

March 4, 2025 5:19 pm

Dr. Spencer: I got a much needed smile from your tongue-in-cheek message. Thanks for that.

But, seriously, I do wonder about the amount of water vapour discharged into the stratosphere from jet aircraft, and whether it has any effect on climate. I started pondering on this when I read opinions about the Hunga Tonga eruption discharging so many cubic kilometres of water into the stratosphere and maybe causing a spike in global temperature. You can look up the annual global consumption of jet fuel (it’s a heck of a lot), make an assumption about how much is burned in the stratosphere versus the troposphere, and the arithmetic is simple.

Tangential question: What might have been the effect of the millions of tons of salt (after all, it was mostly sea water) that Hunga Tonga discharged into the stratosphere? There’s a question for the WUWT pundits to chew on…

Michael Flynn
March 4, 2025 7:15 pm

Dr Spencer-

You wrote –

The amount of water vapor in the atmosphere (did I forget to mention it’s our main greenhouse gas?)”

I do hope that you are not implying that adding “greenhouse gases” (whatever they are supposed to be) to the air makes the air hotter? Or, that removing “greenhouse gases” from the air results in cooling?

That would appear to be contrary to the laws of physics, not to mention observed reality.

Removing the “main greenhouse gas” from the atmosphere in locations like Death Valley or the Lut desert results not in cooling, but the hottest air temperatures on the planet!

Are you simply confused, perhaps?

March 4, 2025 7:19 pm

But what about water vapor emissions from such vehicles?

Currently, our transportation sector partitions the byproduct of ICE vehicles between CO2 and H2O. If we do away with hydrocarbons and transition to a hydrogen economy as some are advocating, all of the exhaust will be H2O! Not only will it contribute to a rise in the heat index, especially in transportation corridors, but it will also contribute to slick pavements all the time, increasing braking distance, and contribute to rime ice in the Winter. Mold and corrosion of unprotected metal will also become more of a problem. I’m reminded of the old adage of “Better the Devil I know than the one I don’t know.”

March 4, 2025 11:56 pm

Well I have long wondered that if you buy the positive feedback scenario, that CO2 warms the atmosphere, and that then relative humidity will stay the same and then increased water vapor will cause a runaway feedback, because water vapor is an even more potent GH gas than CO2, then why doesn’t H2O just create its own feedback loop?

All the same triggers are there, it warms the atmosphere reducing relative humidity, not to mention there is an almost unlimited supply of water thats constantly turning into vapor over most of the earth.

If there is some sort of mechanism, like cloud forming, or rain, that prevents water which is on average 2 orders of magnitude more concentrated in the atmosphere from creating its own feedback loop, why doesn’t that same mechanism also prevent CO2 from creating positive feedback?

Silly question, I know, but I don’t have an answer.

March 5, 2025 1:04 am

 “we can’t stop making things cleaner and cleaner”

Sadly that’s the way those politicians/bureaucrats think and work. I attended a meeting regarding a new environmental regulation in my homecountry (Austria) where one of the bureaucrats from the Ministry of Environment presented and explained the regulation (about heavy industry emissions of EUs IED) and in a debate with one of the participants frankly admitted: “From the point of view of the Ministery of Environment the ideal situation would be, if no industry in Austria would be existing.”

You could see the jaws of the participants dropping (including mine) before the bureaucrat got confronted with some harsh words. But you can be sure that none of those changed his mind, or was even given as feedback to the hierarchy levels above.

Sparta Nova 4
Reply to  Gerald
March 5, 2025 1:18 pm

The laws of diminishing returns have been scrapped.

There is always: perfection is unobtanium.

Uzi1
March 6, 2025 6:21 pm

In the thoughts of stupid bought and corrupted “climate effups” scientists, it’s time for a water vapor tax….kiss my axx EPA….