Cleaner air’s impact requires a steeper reduction in human-emitted methane to meet global targets.
A new study reveals that reducing sulfur pollution in the air could unintentionally increase methane emissions from natural wetlands, including peatlands and swamps.
Published in Science Advances, the research suggests that declining global sulfur emissions—driven by clean air policies—combined with the warming and fertilizing effects of carbon dioxide, are fueling greater methane production in wetlands.
This additional release of 20–34 million tonnes of methane per year could make it more challenging to meet climate targets. As a result, efforts to reduce human-caused methane emissions may need to be even more ambitious than those outlined in the Global Methane Pledge.
Methane, which is one of the most potent greenhouse gases in trapping heat in the atmosphere, is produced in wetlands around the world. Sulfur (in the form of sulfate) has a very specific effect in natural wetlands that reduces methane emissions, while CO2 increases methane production by increasing growth in plants that make the food for methane-producing microbes.
The Unintended Consequences of Clean Air Policies
Professor Vincent Gauci from the University of Birmingham and a senior author of the study said: “Well-meaning policies aimed at reducing atmospheric sulfur appear to be having the unintended consequence of lifting this sulfur ‘lid’ on wetland methane production. This coupled with increased CO2 means we have a double whammy effect that pushes emissions much higher.
“How has this happened? Put simply, sulphur provides the conditions for one set of bacteria to outmuscle another set of microbes that produce methane when they compete over the limited food available in wetlands. Under the conditions of acid rain sulfur pollution during the past century, this was enough to reduce wetland methane emissions by up to 8%.
“Now that clean air policies have been introduced, the unfortunate consequence of reducing sulfur deposition, which does have important and welcome effects for the world’s ecosystems, is that we will need to work much harder than we thought to stay within the safe climate limits set out in the Paris agreement.”
The Global Methane Pledge and Unexpected Climate Feedbacks
More than 150 nations signed up to the Global Methane Pledge at COP26 in Glasgow, which seeks to reduce human-caused emissions of methane by 30% on a 2020 baseline, by 2030.
The study is the latest to implicate reductions in atmospheric sulfur in driving warming at a faster rate than anticipated. In 2020 shipping pollution controls were introduced to reduce emissions of sulphur dioxide and fine particles that are harmful to human health. This reduction in atmospheric sulfur over the oceans has been implicated in larger warming that expected in what has come to be known as ‘termination shock’.
Lead author of the paper Lu Shen of Peking University said: “Our study points to the complexity of the climate system. Representation of these complex biogeochemical interactions has not previously been well integrated into estimates of future methane emissions. We show that it is essential to consider these feedbacks to get a true understanding of the likely future of this important greenhouse gas.”
Reference: “The large role of declining atmospheric sulfate deposition and rising CO2 concentrations in stimulating future wetland CH4 emissions” by Lu Shen, Shushi Peng, Zhen Zhang, Chuan Tong, Jintai Lin, Yang Li, Huiru Zhong, Shuang Ma, Minghao Zhuang and Vincent Gauci, 5 February 2025, Science Advances.
DOI: 10.1126/sciadv.adn1056
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12 Comments
“For every action, there is an equal and opposite reaction.” It is called Unintended Consequences.
However, as usual, there is a lot of arm waving and few facts. The danger from methane is exaggerated, perhaps to make it look to the public like something is being done when it is just throwing money around while running in place.
https://wattsupwiththat.com/2023/03/06/the-misguided-crusade-to-reduce-anthropogenic-methane-emissions/
I have argued for years that lowering carbon lowers OH particles thus creating a negative feedback loop. This was displayed post covid when lockdowns naturally reduced co2 levels, and thus gave my theory from 2015 legs. We either have biased a d agenda driven scientists or alot of average 120 IQ crap in top research positions and I am being generous with a weschler 120
A lot, not alot. No such word. lol
This is probably just a huge waste of time, but here goes.
First and foremost, anytime you change the form of energy you have a loss, whether it be running mechanical energy through gears, sprockets and chains, leavers or hydraulic pumps and cylinders or electrical energy through wires, transformers, motors or breaking a chemical compound down to elements. As for hydrogen being used for a fuel, yes it is the most plentiful element on earth, water (H2O). To separate the hydrogen from the oxygen there are several methods, most efficient is electrolysis, (this takes as much energy as you can get from hydrogen fuel) then you have to liquify it and this take a huge amount of energy to cool it to more than 423 degrees BELOW 0 and keep it that cold until it is used (you thought it cost a lot to air condition your house to keep it 20 degrees cooler than outside, try keeping it over 500 degrees cooler!!) or compressing it to greater than 10,000 psi (a tank rated for 4500 psi that holds less than 1/2 gallon costs over $500 and isn’t nearly strong enough), yes it can be stored in tanks like those used in welding but it would take 106,969.67 tanks (260 cubic feet each) to run a 1000 megawatt (small) plant for 1 hour next is thermal, heat to greater than 3000 degrees F (this takes more energy than you get from hydrogen fuel) separate the hydrogen from the oxygen then cool it down then you still have the same storage issues. Next you can use chemical reaction, as an example if you put sodium metal into water you get an aggressive reaction where the sodium steals the oxygen and half of the hydrogen from the water, again you have the storage issues also this reaction has created sodium hydroxide as a waste byproduct (toxic and very corrosive) that has to be disposed of.
There are similar scenarios for methane conversion also methane is a “hydrocarbon” (CH4) you will have to still sequester (dispose of) your carbon plus you still have the same hydrogen storage issues.
As for the carbon disposal (sequestration) all that is being done is build a “time bomb” that will allow the carbon back into the atmosphere at some future point as well as creating some other nifty features (please note that nifty features comment is VERY sarcastic). By removing the carbon compounds from the air this WILL cause the oxygen content to increase, to what degree I don’t know, what is known for certain is OSHA has stated that an environmental oxygen increase of 1.5% IS A SIGNIFICANT HAZARD (good bye California and any other place that has issues with wild fires, may God have mercy upon your souls). That small increase does cause things to catch fire much easier, burn hotter, spread much faster, end result is it will require 10 to 50 times the amount of materials and manpower to fight the wild fire plus there will probably be a 20% increase of them.
One more thing, on these “greenhouse gasses”, they are being called greenhouse because they reflect infrared radiation. When Mt. Saint Helen blew an annual global temperature drop of 7 degrees was recorded because the debris that was blown into the atmosphere reflected infrared radiation which by the way is the exact same thing these “greenhouse gasses” do, so unless these tiny little molecules have figured out how to have only 1 shiny side AND figured out how to keep it facing the planet earth they can’t won’t and don’t cause global warming, cooling, yes. So again, really clean the air super good and mama nature is gonna stick it to ya !! Clean up the atmosphere, yes I love breathing good clean air, yes respect the environment, absolutely!
As for sea level (oceans) rising, try this experiment, take a plastic tumbler (plastic water glass), fill it with water, Freeze it, get another container that’s a little taller and a little bigger around, take your “iceberg” out of the cup put it into your bigger container add enough water so your iceberg is floating off the bottom (please note that 10% of it is above the top of the water) mark the level of the water, wait for the iceberg to melt and see what happened to the water level. Just for orneriness, if you don’t know why it didn’t change I gonna let you figure it out.
All information obtained from google
coal BTU/Lb. 8100 to 13000 Bituminous (soft coal) 12000 anthracite (hard coal) 13000
a 1000 mega watt power plant will use 375 tons coal per hour. 12,000 X 2,000 = 24,000,000 X 375 = 9,000,000,000 BTU to run for 1 hour
formula for methane CH4
Hydrogen gas 323.6 BTU per cubic foot
Hydrogen gas 848.64 cubic feet to liquid 1 cubic foot
Hydrogen liquid BTU 274,619.904 per cubic foot
9,000,000,000 BTU to run for 1 hour = 32,772.5699 liquid cubic feet or 27,812,113.72 gas cubic feet or large welding cylinder at 260 cubic feet = 106,969.6682 tanks per hour or 29.714 tanks per second or 17,970,904.25 tanks per week.
for liquid pressure tanks are not practical, so cryogenic is the only feasible approach for a 6 month supply the tank will have to hold more than 1,007,559,898 cubic feet or 7,556,699,168 gallons. For a visualizable thing a 12 foot by 12 foot room with an 8 foot ceiling height is 1152 cubic feet, it will take a tank equal to 874,617.9592 rooms plus the outer walls with insulation. Oh don’t forget, it needs to be kept at below 423 degrees below 0 !! and you thought that your electric bill was bad just to keep your house at 70 degrees.
Ernie, while I’m generally sympathetic with your position, some of your science needs correction. To avoid repeating that I have previously written, please read my comment at https://scitechdaily.com/hydrogen-in-minutes-the-microwave-innovation-changing-clean-energy/#comment-873628
It is about a method of generating hydrogen that you didn’t cover.
You are correct about the storage issues being a significant technological problem. A point that you didn’t mention is that hydrogen has a nasty habit of embrittling steel. Thus, tanks, valves, and gas lines are at risk of eventual catastrophic failure. Even slow leaks can be dangerous because hydrogen has a wider range of hydrogen-to-oxygen mixing ratios that are explosive than any other gas. Related to that is that hydrogen flames are virtually invisible to the eye and one could have a leak that has ignited and not be aware of it.
Yes, storing CO2 underground under pressure is a disaster waiting to happen, especially where earthquakes happen. However, geologists are aware of the risk and Iceland has conducted experiments injecting CO2 underground into rocks that contain minerals like olivine and pyroxenes that are metastable at temperatures of surface rocks. The CO2 reacts with the minerals to create stable serpentine and calcite, which can only be decomposed by heating (calcining) the rocks.
You said, “By removing the carbon compounds from the air this WILL cause the oxygen content to increase, …” I think you have this backwards. When hydrocarbons are burned (oxidized) they produce CO2 and H2O. If CO2 is sequestered, the oxygen that was originally in the atmosphere is now sequestered along with the carbon. Thus, the long term effect might be to REDUCE the oxygen in the atmosphere. However, I’m not overly worried about that because plants, which produce oxygen, like CO2 and I doubt that any large-scale industrial process(es) will capture all the CO2.
Greenhouse gases don’t actually “reflect” IR in the same manner that a mirror reflects light. H2O and CO2 are capable of absorbing IR electromagnetic radiation impinging from any direction. The absorption bands are only receptive to IR radiation characteristic of a Black Body with temperatures similar to the surface of the Earth, which means that the gas molecules are primarily energized from below, regardless of the orientation of the individual gas molecules. Once the GH gas absorbs one or more photons, it likes to shed the increased energy. It does so by releasing IR photons in ALL directions. The top hemisphere sends its photons out into space. However, the photons from the lower hemisphere of the molecules head back to Earth, where they may either be reflected back up (to again run the gantlet of GH gas molecules), or be absorbed and increase the temperature of of the surface. So, in effect, it is more complex than a simple reflection off a mirror, and the apparent reflectivity varies with the roughness of the surfaces, the complex (as in imaginary numbers) refractive index, and the angle of incidence, all details that we can ignore for this discussion.
The question that is unanswered is whether it is a positive feedback situation creating an inevitable, continuing increase in temperature, or whether things like clouds increase the Earth’s albedo and create a countering negative feedback. I’d put my money on a negative feedback because after more than 4.5 billion years, and hot house and ice house climates, we have never gotten stuck in the hot house climate.
Your hydrogen example show how inefficiently it is for energy storage, and doing it creates a giant explosive bomb (Hindenburg). Just not practical. Hydrocarbon fuels are perfect, practical and efficient energy storage, let’s keep using them and stop demonizing what works well.
Follow the money. It’s been stated many times in the past that the climate has experienced non human driven change that is similar to if not worse than what we now see or anticipate to see in the future. I assume that, if billions of years and evolution are real then I assume that a pre human/mammal existence must have seen the same or even higher methane levels than what we are projecting to see. If true, than human involvement and a need for it to be reduced is insignificant.
Climate change itself is now a handy and convenient term that is used to explain every weather and environmental anomaly and naturally anticipated event regardless of its impact on the planet. If I was to tell you 6000 years ago that the environment would repeatedly follow its climatic cycles on a yearly basis for as long as the earth remains, would you, in 2025, say that has thus far been an accurate statement worthy of being trusted or just a lucky happenstance?
The impact of methane on warming is considerably exaggerated. Ignoring for the moment whether feedback loops tend to stabilize the climate through processes such as increasing cloudiness when it gets warmer, and just how important CO2 is in the long-term climate, just doing a quantitative comparison of the Global Warming Potential of methane to carbon dioxide shows that total methane plays a negligible role, let alone anthropogenic methane. Please read the following:
https://wattsupwiththat.com/2023/03/06/the-misguided-crusade-to-reduce-anthropogenic-methane-emissions/
Stop farting, everybody!
Seriously, when 2024 YR4 hits, we’re all going to have a decades long class in climate change, and there’s not a thing we can do about it. So, sit back and have a cold one.
if 2024 yr4 hits the moon there’s no air , no ocean , no tsunami, no dark ages, no fireballs, and you’d be in a nice pressurized cave and be fine. we didn’t bother setting out an outpost. we don’t even have a backup of our precious data. its 30 million $
We are doomed if we do and doomed if we don’t. We are just doomed…
We can go to the moon and coordinate catastrophe from there. The real issue is the phytoplankton to the mantra rays and the methanogenic bacteria. When scavengers are gone , we don’t get to breathe, the Manta Ray has a giant brain for a reason, and sharks are only a Billion in the whole ocean estimated. we are at 8 and we inflected at 3. Its to the moon or , well resources and land are the cause of conflict. It time to go. Bioreactors, growing food, burn coal as much as you want, bring solar concentrators and nitrogen, it 600 million $