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anlomedadOh radicals, where are you?! Meanwhile, the methane-bombing OH radicals are decreasing with decreasing NOx pollution from cars: <a href="https://www.science.org/doi/10.1126/sciadv.adn1115" rel="nofollow noopener" translate="no" target="_blank">https://www.science.org/doi/10.1126/sciadv.adn1115</a> "Interannual changes in atmospheric oxidation over forests determined from space" <a href="https://climatejustice.social/tags/Shuttler" class="mention hashtag" rel="nofollow noopener" target="_blank">#Shuttler</a> et al 2024And 7% more water vapour per 1°C warming means fewer radicals are born: <a href="https://www.science.org/doi/10.1126/science.adn0415" rel="nofollow noopener" translate="no" target="_blank">https://www.science.org/doi/10.1126/science.adn0415</a> "Resetting tropospheric OH and CH4 lifetime with ultraviolet H2O absorption", <a href="https://climatejustice.social/tags/Prather" class="mention hashtag" rel="nofollow noopener" target="_blank">#Prather</a> et al 2024 Water vapour lowers UV radiation from the sun. UV is necessary to trigger excitement in NOx and ozone to produce the radicals. Particularly during <a href="https://climatejustice.social/tags/ElNino" class="mention hashtag" rel="nofollow noopener" target="_blank">#ElNino</a>, the two factors above, water vapour and NOx, lower the OH concentrations in the tropics <a href="https://acp.copernicus.org/articles/21/6481/2021/" rel="nofollow noopener" translate="no" target="_blank">https://acp.copernicus.org/articles/21/6481/2021/</a> "Spatial and temporal variability in the hydroxyl (OH) radical: understanding the role of large-scale climate features and their influence on OH through its dynamical and photochemical drivers" <a href="https://climatejustice.social/tags/Anderson" class="mention hashtag" rel="nofollow noopener" target="_blank">#Anderson</a> et al. 2021 Aha! I had thought that La Nina increases CH4 growth, but it's during El Nino when OH radicals are scarcer. Also Indian Ocean Dipole reigns over radicals in India's methane sources, ie landfills, rice paddies and wetlands. We need more radicals! <a href="https://climatejustice.social/tags/anloCH4" class="mention hashtag" rel="nofollow noopener" target="_blank">#anloCH4</a> <a href="https://climatejustice.social/tags/CH4" class="mention hashtag" rel="nofollow noopener" target="_blank">#CH4</a> <a href="https://climatejustice.social/tags/climate" class="mention hashtag" rel="nofollow noopener" target="_blank">#climate</a> <a href="https://climatejustice.social/tags/atmosphere" class="mention hashtag" rel="nofollow noopener" target="_blank">#atmosphere</a>

anlomedadOH radicals are born if NOx is hit by UV radiation in sunlight. (And water vapour in the air reduces this OH-birthing process, see posts above.) OH Radicals only have a very short lifetime of less than a few seconds because they bomb anything to bits that comes their way, or rather, they react with anything in their neighborhood. If a <a href="https://climatejustice.social/tags/methane" class="mention hashtag" rel="nofollow noopener" target="_blank">#methane</a> molecule is bombed by OH radicals, the result is water vapour and CO2. NOx is born in cow and pig shit, in artificial fertilizer, and also in high-heat combustion processes like lightening strikes, forest fires, and cars, trucks, planes, and ships. NOx and the chemicals born when NOx is hit by UV sunlight (eg ozone), are harmful to living beings. So anthropogenic NOx gets reduced technologically after national and regional <a href="https://climatejustice.social/tags/CleanAir" class="mention hashtag" rel="nofollow noopener" target="_blank">#CleanAir</a> regulations. And by the international shipping organisation IMO, see eg <a href="https://www.ukpandi.com/news-and-resources/articles/2022/imo-tier-iii-nitrogen-oxide-nox-emission-compliance/" rel="nofollow noopener" translate="no" target="_blank">https://www.ukpandi.com/news-and-resources/articles/2022/imo-tier-iii-nitrogen-oxide-nox-emission-compliance/</a> It also describes some techy ways for reducing NOx emissions during fuel combustion. IIUC, <a href="https://climatejustice.social/tags/diesel" class="mention hashtag" rel="nofollow noopener" target="_blank">#diesel</a> engines burn fuel at higher heat than Otto motors. This makes diesel motors more efficient, leading to less CO2 emissions per km – but to more <a href="https://climatejustice.social/tags/NOx" class="mention hashtag" rel="nofollow noopener" target="_blank">#NOx</a>. Which must then be scrubbed from the exhaust. We all recall the two (!) diesel scandals 2004 and 2015 where European car industry was found to cheat deliberately wrt NOx from diesel. (Cheating isn't the right word when you consider that people get sick and die from NOx' ozone pollution. Hence the regulations. And people with the car industry know this – so their cheating is really murder according to German law and recent verdicts [on other cases but with similar circumstances relevant to the legal definition of <a href="https://climatejustice.social/tags/murder" class="mention hashtag" rel="nofollow noopener" target="_blank">#murder</a>]. The fact that German state attorneys chose to only prosecute the fraud speaks volumes wrt how car-centred their minds work. IMO, those managers and engineers should spend their lives in a prison cell. <a href="https://climatejustice.social/tags/Dieselgate" class="mention hashtag" rel="nofollow noopener" target="_blank">#Dieselgate</a> <a href="https://climatejustice.social/tags/CleanDiesel" class="mention hashtag" rel="nofollow noopener" target="_blank">#CleanDiesel</a> Together with the software manufacturers at <a href="https://climatejustice.social/tags/Bosch" class="mention hashtag" rel="nofollow noopener" target="_blank">#Bosch</a>, and the Rex Tillersons of this world. <a href="https://climatejustice.social/tags/ExxonKnew" class="mention hashtag" rel="nofollow noopener" target="_blank">#ExxonKnew</a> Murderous cheating wrt Otto motors is also known <a href="https://de.wikipedia.org/wiki/Abgasskandal#Manipulation_bei_Fahrzeugen_mit_Ottomotoren" rel="nofollow noopener" translate="no" target="_blank">https://de.wikipedia.org/wiki/Abgasskandal#Manipulation_bei_Fahrzeugen_mit_Ottomotoren</a> Here it is a software for reducing <a href="https://climatejustice.social/tags/CO2" class="mention hashtag" rel="nofollow noopener" target="_blank">#CO2</a> emissions on the testing stand. )Anyway. Where was I? Ah, yes, the NOx-creation process and how these give birth to OH radicals in UV sunlight: OH radicals are born when UV sunlight hits NOx molecules. After only a few seconds, the suicidal radical bombs a suitable molecule like methane. But new radicals are born all day long. Because NOx is replenished constantly, in lightening strikes, forest fires, burning fossil fuels in🏭🏠, and:🚗🚚✈️🚢Together with the new finding that more moisture in the air due to global warming reduces UV sunlight, and hence reduces the births of OH radicals, which in turn increases CH4 lifetime <a href="https://www.science.org/doi/10.1126/science.adn0415" rel="nofollow noopener" translate="no" target="_blank">https://www.science.org/doi/10.1126/science.adn0415</a> <a href="https://climatejustice.social/tags/Prather" class="mention hashtag" rel="nofollow noopener" target="_blank">#Prather</a> et al 2024🔒 I have been also wondering for a few years now whether NOx regulations and technological scrubbing (where it does occur, harr harr), and also a serious electrification in transport, industry and homes already have, and will have later on, a sufficiently large effect on increasing CH4 lifetime. And I am wondering again whether a reduced NOx abundance during the warm=wet and less fire-prone, stronger forested <a href="https://climatejustice.social/tags/Miocene" class="mention hashtag" rel="nofollow noopener" target="_blank">#Miocene</a> caused CH4 to linger for longer because fewer OH radicals were born. Adding the new finding to this theory, that more water vapour decreases OH concentration, makes my theory even more pertinent: With high temperatures during the miocene at surprisingly low CO2 values, methane could explain parts of the discrepancy. But we don't have proxies for methane concentration. Kind of important because today's climate sensitivity for doubling CO2 = 3°C, is in part fed by findings in <a href="https://climatejustice.social/tags/paleoclimate" class="mention hashtag" rel="nofollow noopener" target="_blank">#paleoclimate</a> such as the Miocene. The Miocene had a different land mass layout, different ocean currents, and also different biomes, hydrological cycle and whatnot. So it's not a good analog for our experiment today as I often point out, eg in this thread <a href="https://climatejustice.social/@anlomedad/112767092856263574" rel="nofollow noopener" translate="no" target="_blank">https://climatejustice.social/@anlomedad/112767092856263574</a> It's also mentioned in passing in Gavin Schmidt's new blog post about the paper that had prompted my thread above, with its spurious claim of climate sensitivity. <a href="https://www.realclimate.org/index.php/archives/2024/08/oh-my-oh-miocene/#ITEM-25598-4" rel="nofollow noopener" translate="no" target="_blank">https://www.realclimate.org/index.php/archives/2024/08/oh-my-oh-miocene/#ITEM-25598-4</a> So these system setting differences explain part of the temperature/CO2 discrepancy. But not all. <a href="https://climatejustice.social/tags/anloCH4" class="mention hashtag" rel="nofollow noopener" target="_blank">#anloCH4</a> <a href="https://climatejustice.social/tags/anloOH" class="mention hashtag" rel="nofollow noopener" target="_blank">#anloOH</a>

anlomedadThe study on how increased water vapour reduces the concentration of OH radicals by filtering UV-light, and thus, extending the lifetime of <a href="https://climatejustice.social/tags/methane" class="mention hashtag" rel="nofollow noopener" target="_blank">#methane</a> in the <a href="https://climatejustice.social/tags/atmosphere" class="mention hashtag" rel="nofollow noopener" target="_blank">#atmosphere</a>: <a href="https://www.science.org/doi/10.1126/science.adn0415" rel="nofollow noopener" translate="no" target="_blank">https://www.science.org/doi/10.1126/science.adn0415</a> 🔒 <a href="https://climatejustice.social/tags/Prather" class="mention hashtag" rel="nofollow noopener" target="_blank">#Prather</a> et al 2024 "Resetting tropospheric OH and CH4 lifetime with ultraviolet H2O absorption"A side note: The suggested replacement of hard-to-abate fossil fuels with hydrogen in steel industry or shipping, makes the discovery of the connection water vapour ↘️ OH radicals ↗️ CH4 lifetimeeven worse. Considering that <a href="https://climatejustice.social/tags/climateChange" class="mention hashtag" rel="nofollow noopener" target="_blank">#climateChange</a> increases methane emissions from natural sources due to more wetlands and thawing permafrost becoming active peat land, we're all the more dependent on OH radicals bombing CH4 molecules to bits. But the leaky supply chain of hydrogen will further increase water vapour – by also using up OH radicals for this reaction – hence, serious use of hydrogen in industry or heavy transport will further decrease OH concentration, which is already decreasing due to warmer air holding more moisture, as the study apparently shows. <a href="https://climatejustice.social/tags/Openaccess" class="mention hashtag" rel="nofollow noopener" target="_blank">#Openaccess</a> should be mandatory!! <a href="https://climatejustice.social/tags/anloCH4" class="mention hashtag" rel="nofollow noopener" target="_blank">#anloCH4</a> <a href="https://climatejustice.social/tags/anloOH" class="mention hashtag" rel="nofollow noopener" target="_blank">#anloOH</a>

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