Introduction
Authors: Boyer Tim , Bartow-Gillies Ellen , Abida A. , Ades Melanie , Adler Robert , Adusumilli Susheel , Agyakwah W. , Ahmasuk Brandon , Aldeco Laura S. , Alexe Mihai , Alfaro Eric J. , Allan Richard P. , Allgood Adam , Alves Lincoln. M. , Amador Jorge A. , Anderson John , Andrade B. , Anneville Orlane , Aono Yasuyuki , Arguez Anthony , Arosio Carlo , Atkinson C. , Augustine John A. , Avalos Grinia , Azorin-Molina Cesar , Backensto Stacia A. , Bader Stephan , Baez Julian , Baiman Rebecca , Ballinger Thomas J. , Banwell Alison F. , Bardin M. Yu , Barichivich Jonathan , Barnes John E. , Barreira Sandra , Beadling Rebecca L. , Beck Hylke E. , Becker Emily J. , Bekele E. , Bellido Guillem Martín , Bellouin Nicolas , Benedetti Angela , Benestad Rasmus , Berne Christine , Berner Logan. T. , Bernhard Germar H. , Bhatt Uma S. , Bhuiyan A. E. , Bigalke Siiri , Biló Tiago , Bissolli Peter , Bjerke Jarle W. , Blagrave Kevin , Blake Eric S. , Blenkinsop Stephen , Blunden Jessica , Bochníček Oliver , Bock Olivier , Bodin Xavier , Bosilovich Michael , Boucher Olivier , Bozkurt Deniz , Brettschneider Brian , Bringas Francis G. , Bringas Francis , Buechler Dennis , Buehler Stefan A. , Bukunt Brandon , Calderón Blanca , Camargo Suzana J. , Campbell Jayaka , Campos Diego , Carrea Laura , Carter Brendan R. , Cetinić Ivona , Chambers Don P. , Chan Duo , Chandler Elise , Chang Kai-Lan , Chen Hua , Chen Lin , Cheng Lijing , Cheng Vincent Y. S. , Chomiak Leah , Christiansen Hanne H. , Christy John R. , Chung Eui-Seok , Ciasto Laura M. , Clarke Leonardo , Clem Kyle R. , Clingan Scott , Coelho Caio A.S. , Cohen Judah L. , Coldewey-Egbers Melanie , Colwell Steve , Cooper Owen R. , Cornes Richard C. , Correa Kris , Costa Felipe , Covey Curt , Coy Lawrence , Créatux Jean-François , Crhova Lenka , Crimmins Theresa , Cronin Meghan F. , Cropper Thomas , Crotwell Molly , Culpepper Joshua , Cunha Ana P. , Cusicanqui Diego , Datta Rajashree T. , Davis Sean M. , De Bock Veerle , de Jeu Richard A. M. , De Laat Jos , Decharme Bertrand , Degenstein Doug , Delaloye Reynald , Demircan Mesut , Derksen Chris , Deus Ricardo , Dhurmea K. R. , Diamond Howard J. , Dirkse S. , Divine Dmitry , Dokulil Martin T. , Donat Markus G. , Dong Shenfu , Dorigo Wouter A. , Drost Jensen Caroline , Druckenmiller Matthew L. , Drumond Paula , du Plessis Marcel , Dugan Hilary A. , Dulamsuren Dashkhuu , Dunmire Devon , Dunn Robert J. H. , Durre Imke , Dutton Geoff , Duveiller Gregory , Ekici Mithat , Elias Chereque Alesksandra , ElKharrim M. , Epstein Howard E. , Espinoza Jhan-Carlo , Estilow Thomas W. , Estrella Nicole , Fauchereau Nicolas , Fausto Robert S. , Feely Richard A. , Fenimore Chris , Fereday David , Fettweis Xavier , Fioletov vitali E. , Flemming Johannes , Fogarty Chris , Fogt Ryan L. , Forbes Bruce C. , Foster Michael J. , Franz Bryan A. , Freeman Natalie M. , Fricker Helen A. , Frith Stacey M. , Froidevaux Lucien , Frost Gerald V. , Fuhrman Steven , Füllekrug Martin , Ganter Catherine , Gao Meng , Gardner Alex S. , Garforth Judith , Garg Jay , Gerland Sebastian , Gibbes Badin , Gille Sarah T. , Gilson John , Gleason Karin , Gobron Nadine , Goetz Scott J. , Goldenberg Stanley B. , Goni Gustavo , Goodman Steven , Goto Atsushi , Grooß Jens-Uwe , Gruber Alexander , Gu Guojun , Guard Charles “Chip” P. , Hagos S. , Hahn Sebastian , Haimberger Leopold , Hall Bradley D. , Hamlington Benjamin D. , Hanna Edward , Hanssen-Bauer Inger , Harnos Daniel S. , Harris Ian , He Qiong , Heim Richard R. , Hellström Sverker , Hemming Deborah L. , Hendricks Stefan , Hicks J. , Hidalgo Hugo G. , Hirschi Martin , Ho Shu-peng , Hobbs W. , Holmes Robert M. , Holzworth Robert , Hrbáček Filip , Hu Guojie , Hu Zeng-Zhen , Huang Boyin , Huang Hongjie , Hurst Dale F. , Ialongo Iolanda , Inness Antje , Isaksen Ketil , Ishii Masayoshi , Jadra Gerardo , Jevrejeva Svetlana , John Viju O. , Johns W. , Johnsen Bjørn , Johnson Bryan , Johnson Gregory C. , Jones Philip D. , Jones Timothy , Josey Simon A. , Jumaux G. , Junod Robert , Kääb Andreas , Kabidi K. , Kaiser Johannes W. , Kaler Robb S.A. , Kaleschke Lars , Kaufmann Viktor , Kazemi Amin Fazl , Keller Linda M. , Kellerer-Pirklbauer Andreas , Kendon Mike , Kennedy John , Kent Elizabeth C. , Kerr Kenneth , Khan Valentina , Khiem Mai Van , Kidd Richard , Kim Mi Ju , Kim Seong-Joong , Kipling Zak , Klotzbach Philip J. , Knaff John A. , Koppa Akash , Korshunova Natalia N. , Kraemer Benjamin M. , Kramarova Natalya A. , Kruger A. C. , Kruger Andries , Kumar Arun , L’Heureux Michelle , La Fuente Sofia , Laas Alo , Labe Zachary M. , Lader Rick , Lakatos Mónika , Lakkala Kaisa , Lam Hoang Phuc , Lan Xin , Landschützer Peter , Landsea Chris W. , Lang Timothy , Lankhorst Matthias , Lantz Kathleen O. , Lara Mark J. , Lavado-Casimiro Waldo , Lavers David A. , Lazzara Matthew A. , Leblanc Thierry , Lee Tsz-Cheung , Leibensperger Eric M. , Lennard Chris , Leuliette Eric , Leung Kinson H. Y. , Lieser Jan L. , Likso Tanja , Lin I-I. , Lindsey Jackie , Liu Yakun , Locarnini Ricardo , Loeb Norman G. , Loomis Bryant D. , Lorrey Andrew M. , Loyola Diego , Lu Rui , Lumpkin Rick , Luo Jing-Jia , Luojus Kari , Lyman John M. , Maberly Stephen C. , Macander Matthew J. , MacFerrin Michael , MacGilchrist Graeme A. , MacLennan Michelle L. , Madelon Remi , Magee Andrew D. , Magnin Florence , Mamen Jostein , Mankoff Ken D. , Manney Gloria L. , Marcinonienė Izolda , Marengo Jose A. , Marjan Mohammadi , Martínez Ana E. , Massom Robert A. , Matsuzaki Shin-Ichiro , May Linda , Mayer Michael , Mazloff Matthew R. , McAfee Stephanie A. , McBride C. , McCabe Matthew F. , McClelland James W. , McPhaden Michael J. , Mcvicar Tim R. , Mears Carl A. , Meier Walter N. , Mekonnen A. , Menzel Annette , Merchant Christopher J. , Merrifield Mark A. , Meyer Michael F. , Meyers Tristan , Mikolajczyk David E. , Miller John B. , Miralles Diego G. , Misevicius Noelia , Mishonov Alexey , Mitchum Gary T. , Moat Ben I. , Moesinger Leander , Moise Aurel , Molina-Carpio Jorge , Monet Ghislaine , Montzka Stephan A. , Moon Twila A. , Moore G. W. K. , Mora Natali , Morán Johnny , Morehen Claire , Morice Colin , Mostafa A. E. , Mote Thomas L. , Mrekaj Ivan , Mudryk Lawrence , Mühle Jens , Müller Rolf , Nance David , Nash Eric R. , Nerem R. Steven , Newman Paul A. , Nicolas Julien P. , Nieto Juan J. , Noetzli Jeannette , Noll Ben , Norton Taylor , Nyland Kelsey E. , O’Keefe John , Ochwat Naomi , Oikawa Yoshinori , Okunaka Yuka , Osborn Timothy J. , Overland James E. , Park Taejin , Parrington Mark , Parrish Julia K. , Pasch Richard J. , Pascual Ramírez Reynaldo , Pellet Cécile , Pelto Mauri S. , Perčec Tadić Melita , Perovich Donald K. , Petersen Guðrún Nína , Petersen Kyle , Petropavlovskikh Irina , Petty Alek , Pezza Alexandre B. , Pezzi Luciano P. , Phillips Coda , Phoenix Gareth K. , Pierson Don , Pinto Izidine , Pires Vanda , Pitts Michael , Po-Chedley Stephen , Pogliotti Paolo , Poinar Kristin , Polvani Lorenzo , Preimesberger Wolfgang , Price Colin , Pulkkanen Merja , Purkey Sarah G. , Qiu Bo , Quisbert Kenny , Quispe Willy R. , Rajeevan M. , Ramos Andrea M. , Randel William J. , Rantanen Mika , Raphael Marilyn N. , Reagan James , Recalde Cristina , Reid Phillip , Rémy Samuel , Reyes Kohler Alejandra J. , Ricciardulli Lucrezia , Richardson Andrew D. , Ricker Robert , Robinson David A. , Robjhon M. , Rocha Willy , Rodell Matthew , Rodriguez Guisado Esteban , Rodriguez-Fernandez Nemesio , Romanovsky Vladimir E. , Ronchail Josyane , Rosencrans Matthew , Rosenlof Karen H. , Rösner Benjamin , Rösner Henrieke , Rozanov Alexei , Rozkošný Jozef , Rubek Frans , Rusanovskaya Olga O. , Rutishauser This , Sabeerali C. T. , Salinas Roberto , Sánchez-Lugo Ahira , Santee Michelle L. , Santini Marcelo , Sato Katsunari , Sawaengphokhai Parnchai , Sayouri A. , Scambos Theodore , Schenzinger Verena , Schimanke Semjon , Schlegel Robert W. , Schmid Claudia , Schmid Martin , Schneider Udo , Schreck Carl J. , Schultz Cristina , _ _ , Segele Z. T. , Sensoy Serhat , Serbin Shawn P. , Serreze Mark C. , Setiawan Amsari Mudzakir , Sezaki Fumi , Sharma Sapna , Sharp Jonathan D. , Sheffield Gay , Shi Jia-Rui , Shi Lei , Shiklomanov Alexander I. , Shiklomanov Nikolay I. , Shimaraeva Svetlana V. , Shukla R. , Siegel David A. , Silow Eugene A. , Sima F. , Simmons Adrian J. , Smeed David A. , Smith Adam , Smith Sharon L. , Soden Brian J. , Sofieva Viktoria , Souza Everaldo , Sparks Tim H. , Spence-Hemmings Jacqueline , Spencer Robert G. M. , Spillane Sandra , Sreejith O. P. , Srivastava A. K. , Stackhouse Paul W. , Stammerjohn Sharon , Stauffer Ryan , Steinbrecht Wolfgang , Steiner Andrea K. , Stella Jose L. , Stephenson Tannecia S. , Stradiotti Pietro , Strahan Susan E. , Streletskiy Dmitry A. , Surendran Divya E. , Suslova Anya , Svendby Tove , Sweet William , Takahashi Kiyotoshi , Takemura Kazuto , Tank Suzanne E. , Taylor Michael A. , Tedesco Marco , Thackeray Stephen J. , Thiaw W. M. , Thibert Emmanuel , Thoman Richard L. , Thompson Andrew F. , Thompson Philip R. , Tian-Kunze Xiangshan , Timmermans Mary-Louise , Timofeyev Maxim A. , Tobin Skie , Tømmervik Hans , Tourpali Kleareti , Trescilo Lidia , Tretiakov Mikhail , Trewin Blair C. , Triñanes Joaquin A. , Trotman Adrian , Truchelut Ryan E. , Trusel Luke D. , Tye Mari R. , van der A Ronald , van der Schalie Robin , van der Schrier Gerard , Van Meerbeeck Cedric J. , van vliet Arnold J.H. , Vazife Ahad , Verburg Piet , Vernier Jean-Paul , Vimont Isaac J. , Virts Katrina , Vivero Sebastián , Volkov Denis L. , Vömel Holger , Vose Russell S. , Walker Donald A. , Walsh John E. , Wang Bin , Wang Hui , Wang Muyin , Wang Ray H. J. , Wang Xinyue , Wanninkhof Rik , Warnock Taran , Weber Mark , Webster Melinda , Wehrlé Adrian , Wen Caihong , Westberry Toby K. , Widlansky Matthew J. , Wiese David N. , Wild Jeannette D. , Wille Jonathan D. , Willems An , Willett Kate M. , Williams Earle , Willis J. , Wong Takmeng , Wood Kimberly M. , Woolway Richard Iestyn , Xie Ping-Ping , Yang Dedi , Yin Xungang , Yin Ziqi , Zeng Zhenzhong , Zhang Huai-min , Zhang Li , Zhang Peiqun , Zhao Lin , Zhou Xinjia , Zhu Zhiwei , Ziemke Jerry R. , Ziese Markus , Zolkos Scott , Zotta Ruxandra M. , Zou Cheng-Zhi , Allen Jessicca , Camper Amy V. , Haley Bridgette O. , Hammer Gregory , Love-Brotak S. Elizabeth , Ohlmann Laura , Noguchi Lukas , Riddle Deborah B. , Veasey Sara W. 
Published: September 2023

—J. BLUNDEN, T. BOYER, AND E. BARTOW-GILLIES

Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases.

In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022.

Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record.

While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia.

The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations.

In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old.

In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February.

Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded.

A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported.

As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items.

In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities.

On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect.