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Authors: T. Boyer, J. Blunden, R. Dunn, Melanie Ades, Robert Adler, Susheel Adusumilli, W. Agyakwah, Somayeh Ahmadpour, Laura Aldeco, Michael Alexander, Mihai Alexe, Eric Alfaro, Richard Allan, Adam Allgood, Lincoln Alves, Jorge Amador, Dillon Amaya, Charles Amory, John Anderson, B. Andrade, Liss Marie Andreassen, Orlane Anneville, Yasuyuki Aono, Anthony Arguez, Dolores Armenteras Pascual, Carlo Arosio, Elizabeth Asher, John Augustine, Grinia Avalos, Cesar Azorin-Molina, Oscar Baez-Villanueva, Rebecca Baiman, Thomas Ballinger, Alison Banwell, M. Yu. Bardin, J. Barichivich, Sandra Barreira, Rebecca Beadling, Marc Beauchemin, Hylke Beck, Emily Becker, Brian Beckley, E. Bekele, Nicolas Bellouin, Angela Benedetti, Christine Berne, Logan Berner, Germar Bernhard, Uma Bhatt, Siiri Bigalke, Peter Bissolli, Jarle Bjerke, Eric Blake, Josh Blannin, Stephen Blenkinsop, Oliver Bochníček, Olivier Bock, Xavier Bodin, Olivier Bonte, Michael Bosilovich, Olivier Boucher, Jason Box, Deniz Bozkurt, Brian Brettschneider, Francis Bringas, Mike Brubaker, Stefan Buehler, Brandon Bukunt, David Burgess, Amy Butler, Michael Byrne, Blanca Calderón, Suzana Camargo, Jayaka Campbell, Diego Campos, Fabrizio Cappucci, Laura Carrea, Brendan Carter, Randall Cerveny, Ivona Cetinić, Don Chambers, Duo Chan, Elise Chandler, Kai-Lan Chang, Candice Charlton, Jack Chen, Lin Chen, Lijing Cheng, Vincent Cheng, Lucy Chisholm, Hanne Christiansen, John Christy, Eui-Seok Chung, Laura Ciasto, Leonardo Clarke, Kyle Clem, Scott Clingan, Caio A.S. Coelho, Melanie Coldewey-Egbers, Steve Colwell, Owen Cooper, Richard Cornes, Kris Correa, Felipe Costa, Curt Covey, Lawrence Coy, Jean-Francois Crétaux, Theresa Crimmins, Molly Crotwell, Joshua Culpepper, Ana Cunha, Diego Cusicanqui, Rajashree Datta, Sean Davis, Richard de Jeu, Jos de Laat, Pranab Deb, Bertrand Decharme, Doug Degenstein, Reynald Delaloye, Chris Derksen, Howard Diamond, Elizabeth Digangi, S. Dindyal, Dmitry Divine, Martin Dokulil, Markus Donat, Shenfu Dong, Wouter Dorigo, Caroline Drost Jensen, Matthew Druckenmiller, Marcel Du Plessis, Diane Duchemin, Hilary Dugan, Dashkhuu Dulamsuren, Imke Durre, Geoff Dutton, Gregory Duveiller, Craig Earl-Spurr, Paola Echeverría Garcés, Mithat Ekici, Alesksandra Elias Chereque, Shane Elipot, M. Elkharrim, Howard Epstein, Jhan-Carlo Espinoza, Thomas Estilow, Nicole Estrella, Sinead Farrell, Nicolas Fauchereau, Robert Fausto, Richard Feely, Chris Fenimore, David Fereday, Denise Fernandez, Xavier Fettweis, Vitali Fioletov, Johannes Flemming, Caitlyn Florentine, Chris Fogarty, Ryan Fogt, Bruce Forbes, Michael Foster, Bryan Franz, Thomas Frederikse, Helen Fricker, Stacey Frith, Lucien Froidevaux, Gerald Frost, Shanshan Fu, Yao Fu, Martin Füllekrug, Catherine Ganter, Meng Gao, Judith Garforth, Jay Garg, Sebastian Gerland, Artur Gevorgyan, Donata Giglio, Sarah Gille, John Gilson, Karin Gleason, Nadine Gobron, Sophie Godin, Marlos Goes, Stanley Goldenberg, Julio Gómez Camacho, Yolanda González Hernández, Steven Goodman, Atsushi Goto, Garrett Graham, Alice Grimm, Jens-Uwe Grooß, Alexander Gruber, Guojun Gu, Mauro Guglielmin, Sebastian Hahn, Leopold Haimberger, S. Hakmi, Brad Hall, Benjamin Hamlington, Edward Hanna, Inger Hanssen-Bauer, Merritt Harlan, Daniel Harnos, I. Harris, Qiong He, Máret Heatta, Richard Heim, Deborah Hemming, Stefan Hendricks, J. Hicks, Hugo Hidalgo, Martin Hirschi, Shu-Peng (ben) Ho, Will Hobbs, Robert Holzworth, Radley Horton, Filip Hrbáček, Guojie Hu, Zeng-Zhen Hu, Boyin Huang, Hongjie Huang, Dale Hurst, Iolanda Ialongo, Antje Inness, Ketil Isaksen, Masayoshi Ishii, Michael Jacox, Gerardo Jadra, Piyush Jain, Annika Jersild, Jelmer Jeuring, Svetlana Jevrejeva, Gensuo Jia, Viju John, William Johns, Bjørn Johnsen, Bryan Johnson, Gregory Johnson, P. Jones, Simon Josey, G. Jumaux, Robert Junod, Andreas Kääb, K. Kabidi, Johannes Kaiser, Lars Kaleschke, Viktor Kaufmann, Amin Fazl Kazemi, Linda Keller, Andreas Kellerer-Pirklbauer, Michael Kendon, John Kennedy, Yelena Khalatyan, Valentina Khan, Sergey Khaykin, Mai Van Khiem, Richard Kidd, Rachel Killick, Seong-Joong Kim, Tyler King, Zak Kipling, Megan Kirchmeier-Young, Philip Klotzbach, John Knaff, Jack Kohler, Akash Koppa, Natalia Korshunova, Benjamin Kraemer, Natalya Kramarova, Jessica Kromer, A. Kruger, Arun Kumar, Mikael Kuusela, R. Sofia La Fuente, Alo Laas, Zachary Labe, Rick Lader, Leslie Lait, Mónika Lakatos, Kaisa Lakkala, Hoang Phuc Lam, Xin Lan, Peter Landschützer, Chris Landsea, Kathleen Lantz, Jeff Lapierre, Mark Lara, Waldo Lavado-Casimiro, David Lavers, Matthew Lazzara, Thierry Leblanc, Simon Lee, Tsz-Cheung Lee, Eric Leibensperger, Chris Lennard, Eric Leuliette, Michelle L’heureux, Jan Lieser, Ben Liley, I-I Lin, Chao Liu, Yakun Liu, Y. Lo, Ricardo Locarnini, Norman Loeb, Bryant Loomis, Hosmay Lopez, Andrew Lorrey, Diego Loyola, Susan Lozier, Rui Lu, Bartłomiej Luks, Rick Lumpkin, Jing-Jia Luo, Kari Luojus, John Lyman, Matthew Macander, Michael Macferrin, Graeme Macgilchrist, Michelle Maclennan, Andrew Magee, Florence Magnin, Rúna Í. Magnússon, Jostein Mamen, Ken Mankoff, Gloria Manney, Jose Marengo, Mohammadi Marjan, Andreas Marouchos, Rodney Martinez, Robert Massom, Shin-Ichiro Matsuzaki, Tom Matthews, Michael Mayer, C. Mcbride, Michael Mccarthy, Clive Mcmahon, Tim Mcvicar, Carl Mears, Brooke Medley, Walter Meier, Ademe Mekonnen, Annette Menzel, Christopher Merchant, Leo-Juhani Merio, Mark Merrifield, Michael Meyer, Tristan Meyers, David Mikolajczyk, John Miller, Caitlin Minney, Diego Miralles, Alexey Mishonov, Gary Mitchum, Ben Moat, Aurel Moise, Jorge Molina-Carpio, Paul Montesano, Stephan Montzka, Ronald Moody, Twila Moon, Natali Mora, Colin Morice, Isamu Morino, A. Mostafa, Thomas Mote, Ivan Mrekaj, Lawrence Mudryk, Robi Muharsyah, Jens Mühle, Rolf Müller, D. Nance, Christopher Neigh, R. Steven Nerem, Paul Newman, Julien Nicolas, Jeannette Noetzli, Ben Noll, Taylor Norton, Kelsey Nyland, John O’keefe, Mitsuho Oe, Yuka Okunaka, Alexander Orlik, Tim Osborn, James Overland, Finnur Pálsson, Mark Parrington, Richard Pasch, Reynaldo Pascual Ramírez, Linda Paterson, Cécile Pellet, Mauri Pelto, Renellys Perez, Donald Perovich, Kyle Petersen, Irina Petropavlovskikh, Alek Petty, Alexandre Pezza, Luciano Pezzi, Coda Phillips, Gareth Phoenix, Don Pierson, Izidine Pinto, Ivenis Pita, Michael Pitts, Stephen Po-Chedley, Paolo Pogliotti, Kristin Poinar, Lorenzo Polvani, Amos Porat, Wolfgang Preimesberger, Colin Price, Sarah Purkey, Willy Quispe, Andrea Ramos, William Randel, Marilyn Raphael, Colin Raymond, James Reagan, Phillip Reid, Samuel Rémy, Hans Ressl, Lucrezia Ricciardulli, Andrew Richardson, Robert Ricker, Patricia Rivera, David Robinson, M. Robjhon, Matthew Rodell, Esteban Rodriguez Guisado, Nemesio Rodríguez-Fernández, Maarit Roebeling, Cassandra Rogers, P. Rohini, Vladimir Romanovsky, Josyane Ronchail, Matthew Rosencrans, Karen Rosenlof, Benjamin Rösner, Alexei Rozanov, Jozef Rozkošný, Olga Rusanovskaya, This Rutishauser, C. Sabeerali, Ryan Said, Tetsu Sakai, Roberto Salinas, Ahira Sánchez-Lugo, Michelle Santee, Louis Sass, Kanako Sato, Parnchai Sawaengphokhai, A. Sayouri, Theodore Scambos, Johan Scheller, Verena Schenzinger, Robert Schlegel, Claudia Schmid, Martin Schmid, Carl Schreck, Cristina Schulz, Z. Segele, Sonia Seneviratne, Serhat Sensoy, Ji-In Seong, Julieta Serna Cuenca, Mark Serreze, Fumi Sezaki, Xi Shao, Sapna Sharma, Jia-Rui Shi, Lei Shi, Nikolay Shiklomanov, Svetlana Shimaraeva, Ryuichiro Shinohara, R. Shukla, Eugene Silow, Adrian Simmons, David Smeed, Adam Smith, Benjamin Smith, Ryan Smith, Sharon Smith, Brian Soden, Viktoria Sofieva, Logan Soldo, Everaldo Souza, Jacqueline Spence-Hemmings, Sandra Spillane, O. Sreejith, A. Srivastava, Jr.Paul Stackhouse, Sharon Stammerjohn, Ryan Stauffer, Wolfgang Steinbrecht, Andrea Steiner, Jose Stella, Tannecia Stephenson, Laura Stevens, Paul Stoy, Pietro Stradiotti, Dmitry Streletskiy, Thea Sukianto, Tove Svendby, William Sweet, Ghassan Taha, Kiyotoshi Takahashi, Kazuto Takemura, Michael Taylor, Marco Tedesco, Stephen Thackeray, W. Thiaw, Emmanuel Thibert, Sandy Thomalla, Richard Thoman, Philip Thompson, Laura Thomson, Thorsteinn Thorsteinsson, Xiangshan Tian-Kunze, Mary-Louise Timmermans, Maxim Timofeyev, Hans Tømmervik, Kleareti Tourpali, Katja Trachte, Blair Trewin, Joaquin Triñanes, Sarat Chandra Tripathy, Emma Tronquo, Adrian Trotman, Ryan Truchelut, Luke Trusel, Katherine Turner, Mari Tye, John Uehling, Ronald van der A, Roderick van der Linden, Robin van der Schalie, Gerard van der Schrier, Cédric van Meerbeeck, Arnold van Vliet, Ahad Vazife, Piet Verburg, Jean-Paul Vernier, Isaac Vimont, R. Virasami, Katrina Virts, Sebastián Vivero, Denis Volkov, Holger Vömel, Russell Vose, Christine Waigl, John Walsh, Bin Wang, Hui Wang, Muyin Wang, Ray Wang, Rik Wanninkhof, Taran Warnock, Mark Weber, Melinda Webster, Adrian Wehrlé, Robert Weller, Toby Westberry, Matthew Widlansky, David Wiese, Jeannette Wild, Kate Willett, Earle Williams, Josh Willis, Gabriel Wolken, Takmeng Wong, Kimberly Wood, Richard Iestyn Woolway, Bert Wouters, Francis Wu, Dedi Yang, Xungang Yin, Ziqi Yin, Lisan Yu, Zhenzhong Zeng, Huai-Min Zhang, Peiqun Zhang, Lin Zhao, Feng Zhong, Zhiwei Zhu, Jerry Ziemke, Markus Ziese, Ruxandra Zotta, Cheng-Zhi Zou
Summary
Abstract —J. Blunden and T. Boyer. In 2023, La Niña conditions that generally prevailed in the eastern Pacific Ocean from mid-2020 into early 2023 gave way to a strong El Niño by October. Atmospheric concentrations of Earth’s major greenhouse gases—carbon dioxide, methane, and nitrous oxide—all increased to record-high levels. The annual global average carbon dioxide concentration in the atmosphere rose to 419.3±0.1 ppm, which is 50% greater than the pre-industrial level. The growth from 2022 to 2023 was 2.8 ppm, the fourth highest in the record since the 1960s. The combined short-term effects of El Niño and the long-term effects of increasing levels of heat-trapping gases in the atmosphere contributed to new records for many essential climate variables reported here. The annual global temperature across land and oceans was the highest in records dating as far back as 1850, with the last seven months (June–December) having each been record warm. Over land, the globally averaged temperature was also record high. Dozens of countries reported record or near-record warmth for the year, including China and continental Europe as a whole (warmest on record), India and Russia (second warmest), and Canada (third warmest). Intense and widespread heatwaves were reported around the world. In Vietnam, an all-time national maximum temperature record of 44.2°C was observed at Tuong Duong on 7 May, surpassing the previous record of 43.4°C at Huong Khe on 20 April 2019. In Brazil, the air temperature reached 44.8°C in Araçuaí in Minas Gerais on 20 November, potentially a new national record and 12.8°C above normal. The effect of rising temperatures was apparent in the cryosphere, where snow cover extent by June 2023 was the smallest in the 56-year record for North America and seventh smallest for the Northern Hemisphere overall. Heatwaves contributed to the greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Due to rapid volume loss beginning in 2021, St. Anna Glacier in Switzerland and Ice Worm Glacier in the United States disappeared completely. In August, as a direct result of glacial thinning over the past 20 years, a glacial lake on a tributary of the Mendenhall Glacier in Alaska burst through its ice dam and caused unprecedented flooding on Mendenhall River near Juneau. Across the Arctic, the annual surface air temperature was the fourth highest in the 124-year record, and summer (July–September) was record warm. Smaller-than-normal snow cover extent in May and June contributed to the third-highest average peak tundra greenness in the 24-year record. In September, Arctic minimum sea ice extent was the fifth smallest in the 45-year satellite record. The 17 lowest September extents have all occurred in the last 17 years. In Antarctica, temperatures for much of the year were up to 6°C above average over the Weddell Sea and along coastal Dronning Maud Land. The Antarctic Peninsula also experienced well-above-average temperatures during the 2022/23 melt season, which contributed to its fourth consecutive summer of above-average surface melt. On 21 February, Antarctic sea ice extent and sea ice area both reached all-time lows, surpassing records set just a year earlier. Over the course of the year, new daily record-low sea ice extents were set on 278 days. In some instances, these daily records were set by a large margin, for example, the extent on 6 July was 1.8 million km 2 lower than the previous record low for that day. Across the global oceans, the annual sea surface temperature was the highest in the 170-year record, far surpassing the previous record of 2016 by 0.13°C. Daily and monthly records were set from March onward, including an historic-high daily global mean sea surface temperature of 18.99°C recorded on 22 August. Approximately 94% of the ocean surface experienced at least one marine heatwave in 2023, while 27% experienced at least one cold spell. Globally averaged ocean heat content from the surface to 2000-m depth was record high in 2023, increasing at a rate equivalent to ∼0.7 Watts per square meter of energy applied over Earth’s surface. Global mean sea level was also record high for the 12th consecutive year, reaching 101.4 mm above the 1993 average when satellite measurements began, an increase of 8.1±1.5 mm over 2022 and the third highest year-over-year increase in the record. A total of 82 named tropical storms were observed during the Northern and Southern Hemispheres’ storm seasons, below the 1991–2020 average of 87. Hurricane Otis became the strongest landfalling hurricane on record for the west coast of Mexico at 140 kt (72 m s −1 ), causing at least 52 fatalities and $12–16 billion U.S. dollars in damage. Freddy became the world’s longest-lived tropical cyclones on record, developing into a tropical cyclone on 6 February and finally dissipating on 12 March. Freddy crossed the full width of the Indian Ocean and made one landfall in Madagascar and two in Mozambique. In the Mediterranean Sea—outside of traditional tropical cyclone basins—heavy rains and flooding from Storm Daniel killed more than 4300 people and left more than 8000 missing in Libya. The record-warm temperatures in 2023 created conditions that helped intensify the hydrological cycle. Measurements of total-column water vapor in the atmosphere were the highest on record, while the fraction of cloud area in the sky was the lowest since records began in 1980. The annual global mean precipitation total over land surfaces for 2023 was among the lowest since 1979, but global one-day maximum totals were close to average, indicating an increase in rainfall intensity. In July, record-high areas of land across the globe (7.9%) experienced extreme drought, breaking the previous record of 6.2% in July 2022. Overall, 29.7% of land experienced moderate or worse categories of drought during the year, also a record. Mexico reported its driest (and hottest) year since the start of its record in 1950. In alignment with hot and prolonged dry conditions, Canada experienced its worst national wildfire season on record. Approximately 15 million hectares burned across the country, which was more than double the previous record from 1989. Smoke from the fires were transported far into the United States and even to western European countries. August to October 2023 was the driest three-month period in Australia in the 104-year record. Millions of hectares of bushfires burned for weeks in the Northern Territory. In South America, extreme drought developed in the latter half of the year through the Amazon basin. By the end of October, the Rio Negro at Manaus, a major tributary of the Amazon River, fell to its lowest water level since records began in 1902. The transition from La Niña to El Niño helped bring relief to the prolonged drought conditions in equatorial eastern Africa. However, El Niño along with positive Indian Ocean dipole conditions also contributed to excessive rainfall that resulted in devastating floods over southeastern Ethiopia, Somalia, and Kenya during October to December that displaced around 1.5 million people. On 5 September, the town of Zagora, Greece, broke a national record for highest daily rainfall (754 mm in 21 hours, after which the station ceased reporting) due to Storm Daniel; this one-day accumulation was close to Zagora’s normal annual total.
Link to HAL – hal-04847360
Link to DOI – 10.1175/2024BAMSStateoftheClimate_Intro.1