Editing Sulfate (section)

==Environmental effects==
Sulfates occur as microscopic particles ([[Particulate|aerosols]]) resulting from [[fossil fuel]] and [[biomass]] combustion. They increase the acidity of the [[Earth's atmosphere|atmosphere]] and form [[acid rain]]. <!-- do sulfate aerosols per se comprise "acid rain" vs. aerobic oxidation of SO2 and SO3 to give H2SO4--> The [[Anaerobic organism|anaerobic]] [[sulfate-reducing bacteria]] ''[[Desulfovibrio]] desulfuricans'' and ''[[Desulfovibrio vulgaris|D. vulgaris]]'' can remove the black [[sulfate crust]] that often tarnishes buildings.<ref>{{cite journal|date= Nov 2006| pages=1075–1079| title=Saving a fragile legacy. Biotechnology and microbiology are increasingly used to preserve and restore the worlds cultural heritage| author=Andrea Rinaldi| journal=EMBO Reports| pmc=1679785| pmid=17077862| doi=10.1038/sj.embor.7400844| volume=7| issue=11}}</ref>

===Main effects on climate===
[[Image:Climate Change Attribution.png|thumb|250px|This figure shows the level of agreement between a [[climate model]] driven by five factors and the [[historical temperature record]]. The negative component identified as "sulfate" is associated with the aerosol emissions blamed for global dimming.]]
{{excerpt|Global dimming#History|paragraph=2}}
[[File:SulufrDioxide2017.png|thumb|left|Sulfur dioxide in the world on April 15, 2017. Note that sulfur dioxide moves through the atmosphere with prevailing winds and thus local sulfur dioxide distributions vary day to day with weather patterns and seasonality.]]
{{excerpt|Global dimming#Causes|paragraph=1|hat=no|files=no}}

====Reversal and accelerated warming====
{{excerpt|Global dimming#Reversal|paragraph=1}}
{{excerpt|Global dimming#Historical cooling|hat=no|files=no}}

{{excerpt|Global dimming#Future|paragraphs=1,3|hat=no|files=no}}

====Hydrological cycle====
{{excerpt|Global dimming#Relationship with water cycle|paragraph=1}}

====Solar geoengineering====
[[File:SPICE SRM overview.jpg|thumb|upright=1.5|alt=refer to caption and image description|Proposed tethered balloon to inject [[aerosols]] into the stratosphere.]]
As the real world had shown the importance of sulfate aerosol concentrations to the global climate, research into the subject accelerated.  Formation of the aerosols and their effects on the atmosphere can be studied in the lab, with methods like [[Ion chromatography|ion-chromatography]] and [[mass spectrometry]]<ref>{{Cite journal |last1=Kobayashi |first1=Yuya |last2=Ide |first2=Yu |last3=Takegawa |first3=Nobuyuki |date=3 April 2021 |title=Development of a novel particle mass spectrometer for online measurements of refractory sulfate aerosols |url=https://doi.org/10.1080/02786826.2020.1852168 |journal=Aerosol Science and Technology |volume=55 |issue=4 |pages=371–386 |doi=10.1080/02786826.2020.1852168 |bibcode=2021AerST..55..371K |s2cid=229506768 |issn=0278-6826}}</ref> Samples of actual particles can be recovered from the [[stratosphere]] using balloons or aircraft,<ref>{{cite journal |url=https://www.researchgate.net/publication/234296252_DUSTER_Aerosol_collection_in_the_stratosphere |journal=Societa Astronomica Italiana |title=The DUSTER experiment: collection and analysis of aerosol in the high stratosphere |author1=Palumbo, P. |author2= A. Rotundi |author3=V. Della Corte |author4=A. Ciucci |author5=L. Colangeli |author6=F. Esposito |author7=E. Mazzotta Epifani |author8=V. Mennella |author9=J.R. Brucato |author10=F.J.M. Rietmeijer |author11=G. J. Flynn |author12=J.-B. Renard   |author13=J.R. Stephens |author14=E. Zona |access-date=19 February 2009 }}</ref> and remote [[satellite]]s were also used for observation.<ref name=":32">{{Cite journal |last1=Myhre |first1=Gunnar |last2=Stordal |first2=Frode |last3=Berglen |first3=Tore F. |last4=Sundet |first4=Jostein K. |last5=Isaksen |first5=Ivar S. A. |date=1 March 2004 |title=Uncertainties in the Radiative Forcing Due to Sulfate Aerosols |journal=Journal of the Atmospheric Sciences |language=EN |volume=61 |issue=5 |pages=485–498 |doi=10.1175/1520-0469(2004)061<0485:UITRFD>2.0.CO;2 |bibcode=2004JAtS...61..485M |s2cid=55623817 |issn=0022-4928|doi-access=free }}</ref> This data is fed into the [[climate model]]s,<ref>{{Cite journal |last1=Zhang |first1=Jie |last2=Furtado |first2=Kalli |last3=Turnock |first3=Steven T. |last4=Mulcahy |first4=Jane P. |last5=Wilcox |first5=Laura J. |last6=Booth |first6=Ben B. |last7=Sexton |first7=David |last8=Wu |first8=Tongwen |last9=Zhang |first9=Fang |last10=Liu |first10=Qianxia |date=22 December 2021 |title=The role of anthropogenic aerosols in the anomalous cooling from 1960 to 1990 in the CMIP6 Earth system models |url=https://acp.copernicus.org/articles/21/18609/2021/ |journal=Atmospheric Chemistry and Physics |volume=21 |issue=4 |pages=18609–18627 |language=en |doi=10.5194/acp-21-18609-2021 |bibcode=2021ACP....2118609Z |doi-access=free }}</ref> as the necessity of accounting for aerosol cooling to truly understand the rate and evolution of warming had long been apparent, with the [[IPCC Second Assessment Report]] being the first to include an estimate of their impact on climate, and every major model able to simulate them by the time [[IPCC Fourth Assessment Report]] was published in 2007.<ref>{{cite web|url=https://earthobservatory.nasa.gov/features/Aerosols/page3.php|title=Aerosols and Incoming Sunlight (Direct Effects)|publisher=[[NASA]]|date=2 November 2010}}</ref> Many scientists also see the other side of this research, which is learning how to cause the same effect artificially.<ref>{{cite web |url=https://www.sciencedaily.com/releases/2006/09/060914182715.htm |title=Stratospheric Injections Could Help Cool Earth, Computer Model Shows | access-date=19 February 2009 |publisher=ScienceDaily |date=15 September 2006 }}</ref> While discussed around the 1990s, if not earlier,<ref>{{cite journal |journal=Phil. Trans. R. Soc. A |year=1996 |volume=366 |pages=4039–56 |title=Global and Arctic climate engineering: numerical model studies |doi=10.1098/rsta.2008.0132 |author1=Launder B. |author2=J.M.T. Thompson |pmid=18757275 |issue=1882 |bibcode=2008RSPTA.366.4039C|doi-access=free }}</ref> stratospheric aerosol injection as a [[solar geoengineering]] method is best associated with [[Paul Crutzen]]'s detailed 2006 proposal.<ref name="Crutzen062" /> Deploying in the stratosphere ensures that the aerosols are at their most effective, and that the progress of clean air measures would not be reversed: more recent research estimated that even under the highest-emission scenario [[Representative Concentration Pathway|RCP 8.5]],  the addition of stratospheric sulfur required to avoid {{convert|4|C-change|F-change}} relative to now (and {{convert|5|C-change|F-change}} relative to the preindustrial) would be effectively offset by the future controls on tropospheric sulfate pollution, and the amount required would be even less for less drastic warming scenarios.<ref name="Visioni2020">{{Cite journal|last1=Visioni|first1=Daniele|last2=Slessarev|first2=Eric |last3=MacMartin|first3=Douglas G|last4=Mahowald|first4=Natalie M|last5=Goodale|first5=Christine L|last6=Xia|first6=Lili|date=1 September 2020|title=What goes up must come down: impacts of deposition in a sulfate geoengineering scenario|journal=Environmental Research Letters|volume=15|issue=9|pages=094063|doi=10.1088/1748-9326/ab94eb|bibcode=2020ERL....15i4063V|issn=1748-9326|doi-access=free}}</ref> This spurred a detailed look at its costs and benefits,<ref>{{cite web |url=http://www.met.reading.ac.uk/pg-research/downloads/2009/pgr-charlton.pdf |title=Costs and benefits of geo-engineering in the Stratosphere |author1=Andrew Charlton-Perez |author2=Eleanor Highwood |access-date=17 February 2009 |archive-date=14 January 2017 |archive-url=https://web.archive.org/web/20170114032949/http://www.met.reading.ac.uk/pg-research/downloads/2009/pgr-charlton.pdf |url-status=dead }}</ref> but even with hundreds of studies into the subject completed by the early 2020s, some notable uncertainties remain.<ref name="IPCC_WGI_SRM" >{{Cite journal |last1=Trisos |first1=Christopher H. |last2=Geden |first2=Oliver |last3=Seneviratne |first3=Sonia I. |last4=Sugiyama |first4=Masahiro |last5=van Aalst |first5=Maarten |last6=Bala |first6=Govindasamy |last7=Mach |first7=Katharine J. |last8=Ginzburg |first8=Veronika |last9=de Coninck |first9=Heleen |last10=Patt |first10=Anthony |title=Cross-Working Group Box SRM: Solar Radiation Modification |url=https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter16.pdf |journal=Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change |year=2021 |volume=2021 |pages=1238 |doi=10.1017/9781009157896.007|bibcode=2021AGUFM.U13B..05K }}</ref>