News

Reconstructions of summer temperatures across western North America spanning the past 500 years suggest that concurrent heat and drought conditions, known as “hot drought,” have been unprecedented in frequency and severity over the past century. The findings are derived from tree-ring chronologies that show how changing temperatures relate to changes in soil moisture. They add to growing evidence that human-influenced warming has exacerbated climate extremes across the region.

The study, by researchers at Columbia University’s Lamont-Doherty Earth Observatory and other institutions, was just published in the journal Science Advances.

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Third graders at Public School 103 in the north Bronx sat on a rug last month while their teacher, Kristy Neumeister, led a book discussion.

The book, “Rain School,” is about children who live in a rural region of Chad, a country in central Africa. Every year, their school must be rebuilt because storms wash it away.

“And what’s causing all these rains and storms and floods?” asked Ms. Neumeister.

“Carbon,” said Aiden, a serious-looking 8-year-old.

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From a climate perspective, 2024 is beginning in uncharted territory. Temperatures last year broke records not by small intervals but by big leaps; 2023 was the hottest year ever recorded, and each month in the second half of the year was the hottest—the hottest June, the hottest July, all the way through to December. July was in fact the hottest month in recorded history. Already, experts predict that 2024 is likely to be even hotter. But these heat records, although important milestones, won’t hold their title for long. “Getting too excited about any given year is a bit of a fool’s game, because we’re on an escalator that’s going up,” Jason Smerdon, a climate scientist at the Columbia Climate School, told me. “We’re going to be doing this every year.”

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Check out all of our lab presentations at AGU this year.  They are listed below in chronological order.  Come by and say hi!

PP32B-03 The Increasing Prevalence of Hot Drought Across Western North America Since the 16th Century
Karen King, Edward R Cook, Kevin J Anchukaitis, Benjamin Cook, Jason E Smerdon, Richard Seager, Grant L. Harley and Benjamin Spei
3022 - West (Level 3, West, MC)
Wednesday, 13 December 2023: 13:42 - 13:52

PP33E-1569 Simultaneous megadroughts in the southwestern regions of North America and South America in last-millennium climate model simulations
Anson H Cheung, Jason E Smerdon, Cuihua Li and Nathan John Steiger
Poster Hall A-C - South (Exhibition Level, South, MC)
Wednesday, 13 December 2023: 17:10 - 21:30

GC34D-04 Drivers of Runoff Efficiency in the Western United States
Alexander Gottlieb, Park Williams, Benjamin Cook, Jason E Smerdon, Justin Mankin
2005 - West (Level 2, West, MC)
Wednesday, 13 December 2023: 19:30 - 19:40

GC41I-1209 Jet dynamics do not explain climate model simulations of muted multidecadal summer precipitation trends in southeastern South America
Arianna Marie Varuolo-Clarke, Jason E Smerdon, and Park Williams
Poster Hall A-C - South (Exhibition Level, South, MC)
Thursday, 14 December 2023: 11:30 - 15:50

GC41K-1237 Climate trends force step changes in drought classifications
Zhiying Li, Richard Seager, Jason E Smerdon, Noel Siegert, and Justin Mankin
Poster Hall A-C - South (Exhibition Level, South, MC)
Thursday, 14 December 2023: 11:30 - 15:50

GC41K-1243 Attribution of the 2020-21 Western US Drought
Yelin Jiang, Jason E Smerdon, Richard Seager, Guiling Wang, Benjamin Cook, Cheng Zheng and Justin S Mankin
Poster Hall A-C - South (Exhibition Level, South, MC)
Thursday, 14 December 2023: 11:30 - 15:50

The Smerdon Climate Lab is excited to welcome a new graduate student and a Lamont Postdoctoral Fellow! Hannah Byrne and Anson Cheung joined Columbia in fall 2023.  Hannah has interests in hydroclimate variability and change and will be working on a collaborative NSF project aimed at understanding how variability in surface ocean temperatures, particularly those in the Pacific Ocean, impact drought patterns around the world.  Her project will be advised jointly with Richard Seager.  Anson is similarly interested in hydroclimate variability, but has an interest in characterizing this variability using paleoclimate information over the last two millennia.

Hannah graduated with a B.A. in Earth and Planetary Sciences from Harvard University in 2018.  Before commencing her graduate studies, Hannah worked in strategy consulting and agricultural technology that included launching a sustainability program focused in part on the climate impacts of food production and disparities in access to fresh produce. As part of her PhD, she is interested in applying a deeper understanding of climate and climate change to pressing issues surrounding food security.

Anson received his B.S. in Geosciences from the University of Arizona and his Ph.D. in Earth, Environmental, and Planetary Sciences from Brown University.  He is a Lamont-Doherty Postdoctoral Fellow and his research focuses on understanding variability of the ocean and the ocean's influence on regional climate and ecosystems using paleoclimate records and climate models.

Welcome Hannah and Anson!

Lab members and friends gathered for a potluck in the park for one last hurrah before Ari leaves and to celebrate the arrival of several new members.  It turns out these folks can cook!  Good food and good fun was had by all.  There was even a bubble machine.

Arianna Varuolo-Clarke is officially a doctor!  Dr. Varuolo-Clarke successfully defended her thesis, titled The Mystery of Observed and Simulated Precipitation Trends in Southeastern South America since the early 20th Century, on June 23rd.  Ari's next step is to the University of Colorado-Boulder where she will work with Jennifer Kay as a NOAA Climate and Global Change Postdoctoral Fellow.  

Graduate student Arianna Varuolo-Clarke has been awarded a prestigious NOAA Climate and Global Change Fellowship.  Ari will defend her doctoral thesis in June, before moving to Boulder to pursue her postdoctoral research with Prof. Jennifer Kay at the University of Colorado, Boulder.  Her proposed project is titled "Investigating drivers of midlatitude precipitation change in a warming world." 

Congrats Ari!  We can't wait to read about all of the new research you complete during your postdoc!

Anson Cheung visited Lamont from Brown University on February 9th and 10th.  Anson's visit was an occasion to gather lab members for an evening dinner.  Arianna Varuolo-Clarke, Ibuki Sugiura, Aandishah Samara, Yelin Jiang, Richard Seager, and Hannah Byrne were able to join.

The Smerdon Climate Lab is excited to welcome Yelin Jiang as a new Postdoctoral Research Scientist.  Yelin received his B.S. and M.S. in Ecology from the School of Applied Meteorology at Nanjing University of Information Science & Technology. He holds a Ph.D. in Environmental Engineering from University of Connecticut. His dissertation was advised by Prof. Guiling Wang and titled “Land-Atmosphere Interactions and Drought over Tropical South America.”

Yelin studies land-atmosphere interactions using numerical models and observational data. He is particularly interested on understanding the role of land-atmosphere interactions in drought development and hydrological change and will be working on a DOE-funded project focused on the role of vegetation in past and future global hydroclimatic change.  Yelin will be co-advised by Jason Smerdon and Richard Seager, in collaboration with the other DOE project PIs including Justin Mankin, Ben Cook, and Park Williams.

Welcome Yelin!

 

Check out all of our lab presentations at AGU.  They are listed below in chronological order.  Come by and say hi!

MONDAY

B16C-07
Nonlinear plant responses to carbon dioxide and climate diminish water availability

Justin Mankin, Noel Siegert, Harmanveer Singh, Emily Martinez, Zhiying Li, Jason E Smerdon, Benjamin Cook, Richard Seager, and Park Williams

 

TUESDAY

NG25A-08
Progress and uncertainties in global and hemispheric temperature reconstructions of the Common Era

Jason Smerdon and Kevin Anchukaitis

 

WEDNESDAY

Day of rest!

 

THURSDAY

PP42B-02
A Climate and History Case Study of 18th- and 19th-Century Multidecadal Droughts in East Africa Using a new Tree-Ring Drought Atlas

Jason E Smerdon, Rhiannon Stephens, Edward Cook, and Benjamin Cook


GC46B-06
Static Drought Assessment in a Nonstationary Climate

Zhiying Li, Justin S Mankin, Richard Seager, Jason E Smerdon, and Noel Siegert

 

FRIDAY

A52B-06
Low-level jet dynamics simulated by CMIP6 models don’t account for their muted estimates of 20th-century precipitation trends in Southeastern South America

Arianna Varuolo-Clarke, Jason Smerdon, and Park Williams

The Smerdon Climate Lab is excited to welcome two new graduate students!  Aandishah Samara and Ibuki Sugiura joined Columbia in fall 2022 as first-year graduate students in the Department of Earth and Environmental Sciences.  Both have interests in hydroclimate variability and change and will be working on two collaborative NSF projects (here and here) aimed at understanding how variability in surface ocean temperatures, particularly those in the Pacific Ocean, impact drought patterns around the world.  Their projects will be advised jointly with Richard Seager.

Aandishah earned her B.A. in Earth System Science and M.S. in Geographical Information Systems at Clark University. Her main interests are climate change, ocean-atmosphere interactions, and applications of remote sensing. She is fascinated by the impacts of climate change on the interactions between the atmosphere and hydrosphere, and the implications for future climate risks and impacts.  Born and raised in Dhaka, Bangladesh, she is also interested in the impacts of climate change on people, especially minority communities. 

Ibuki graduated from Smith College in 2022 with B.A. in Geosciences and Mathematics. She is interested in the ocean’s role in past, modern, and future climates, and she hopes to explore the ocean-atmosphere interactions and their effects on climate change and variability using both paleo and modern data.

Welcome Aandishah and Ibuki!

Gasping salmon with infected lesions. Emaciated deer searching sagebrush flats for water. Clams and mussels boiled to death in their shells. Last summer, temperatures in the Northwest soared to record highs in the triple digits, killing more than 1 billion marine animals in the Salish Sea and stressing wildlife from the Pacific to the Rocky Mountains. Simultaneously, ongoing drought in the Southwest—which began in 2000 and is the region’s driest 22-year period in 1,200 years—is causing plants to wither, springs to dry up and wildfires to engulf entire landscapes.

The new normal is upon us—and its impacts are alarming, both for wildlife and people.

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This is not a drill, or a far-flung fantasy; Southwestern US is facing a critical megadrought. The last two decades have been the driest since 800 CE, and pioneering studies by Columbia Scientists and other institutions have proven that the anthropogenic impact on the climate is a major contributing factor. The water level at the region's two largest reservoirs is at a record low, resulting in contention between seven states and millions of their residents for their diminishing share of hydroelectric power as well as agricultural and residential water demand. This is especially daunting in anticipation of the hottest period of the summer.

Please join this special session as Prof. Jason E. Smerdon, one of the authors of the recent groundbreaking article in Nature Climate Change about this megadrought discusses the unfolding crisis, its trajectory, its economic toll, and its impact on sustainability of life in the region.

Time will be allocated for Q&A.

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The American southwest is in a megadrought. Water levels in lakes are dropping, threatening the local environment as well as agriculture, hydroelectric power, and the people living there. As global temperatures rise, it could be a preview of worse things to come.

Guest: Dr. Jason Smerdon, ocean and climate physicist, and Lamont research professor at the Lamont-Doherty Earth Observatory of Columbia University and co-director at the Earth Institute Faculty.

Listen to the Podcast