Glacier geologists search for global climate clues to support urgent action now

Glacier geologists search for global climate clues to support urgent action now

By Poonam Narotam, Dec. 15, 2021 –
When he’s not teaching earth science classes and analyzing data at the University of Maine, glacier whisperer Aaron Putnam is trekking into the high Himalayas or New Zealand’s Southern Alps to study where glaciers once stood.

The United Nations officials behind the recent global COP26 climate conference urged countries to eliminate carbon emissions by 45% below 2010 levels by 2030 to stabilize global warming driven by fossil fuel use. No definitive commitments were made toward that goal.

Researchers deepen our knowledge of climate systems and models in the hopes of awakening the urgent need for international solutions before global warming hits a tipping point. Putnam asks the big questions vital to modeling future climate patterns: What caused the last global ice age and how did it suddenly end?

“We need this information from the past to help calibrate our understanding of what’s coming in the future,” said Putnam, 40, an associate professor of earth science at the University of Maine.

Putnam is one of many paleoclimate scientists who studied under and worked with George Denton, distinguished professor at the University of Maine’s School of Earth and Climate Sciences and Climate Change Institute. Putnam and Denton spent the better part of a decade developing a new hypothesis published in March introducing how the westerly winds, the earth’s strongest wind system, contribute to climate shifts between glacial (when glaciers grow) and interglacial periods (when glaciers decline). Both scientists discussed their research at the Comer Climate Conference this fall, an annual gathering of international researchers held remotely this year due to the pandemic.

The findings prompted Putnam to look closely at the similarities between modern global warming and the end of the last ice age, the primary difference being that the pace of today’s climate change is escalating due to human-induced carbon emissions. Putnam, along with Denton and other paleoclimate scientists in their group, tested the hypothesis by mapping key glacier sites in both hemispheres. They found this dynamic system could have a dramatic impact on melting ice in the Southern Hemisphere and global sea level rise.

Putnam studies the land and patterns of rocks to identify where glaciers used to be. He draws detailed maps of the ridges and valleys, and collects rock samples. His research teams ship hundreds of pounds of rock to the Maine lab for testing to determine when the ice sheet melted and exposed the rock.

 

Aaron Putnam's Field Notes
Aaron Putnam takes copious notes in his all-weather geological field book and illustrated a boulder he sampled in New Zealand in 2014. “I don’t know how he gets all that detail in there,” said Lauren Woods, 22. “His ability to draw things is astonishing.” Woods first took Putnam’s Habitable Planet Seminar as a college sophomore and studies glacial geology and geochronology as a master’s student with Putnam at the University of Maine. (Photo Credit: Aaron Putnam/UNIVERSITY OF MAINE)

 

Using chemical analysis techniques, graduate students measure the amount of the isotope Beryllium-10 in the rock. The isotope forms in exposed rock when cosmic rays collide with quartz. Piecing together hundreds of precise calculations, Putnam’s team develops a chronology of how that glacier grew and shrank.

As the pandemic prevented travel to Southern Hemisphere glacier sites, Putnam led fieldwork in Wyoming in July to study the Laurentide Ice Sheet, the largest ice sheet of the last ice age. The ice sheet covered the upper half of North America during the ice age and its retreat gouged out the Great Lakes we know today, filling them with meltwater. Expanding glacier chronologies in both hemispheres furthers our understanding of global climate systems and the new patterns Putnam and Denton have been studying.

“We were looking at the surface [of a boulder] to see if it would be good to sample,” said Lauren Woods, a master’s student on the Wyoming trip. “He just kind of leans down to the rock and whispers, ‘Tell us your secrets.’”

Reaching remote field sites

Glacier research also requires finding the right combination of flights, boating routes, drives and treks into some of the world’s most remote places. Putnam said it took his team a week to traverse the Lunana Snowman trek on the border of Bhutan and Tibet, a snowy route amongst glaciers along the main spine of the Himalayas

Disconnected from mainstream communications and living among communities that don’t speak English, Putnam’s group relies heavily on local guides to coordinate directions, emergencies, and food.

Putnam’s Ph.D. student Peter Strand said they bought a sheep from a local herder in Mongolia to keep everyone fed.

“It’s not a good place in the world to be a vegetarian,” said Strand, who jumped at the opportunity to sign on as Putnam’s first Ph.D. student.

“He’s always encouraging everyone to think big,” Strand said. He said Putnam prompts them with the question: “What can this really tell us about how the whole earth system works?”

Without much cell phone coverage, Putnam said he feels more present and able to think in the “glacial graveyards,” areas of land marked by bodies of water and ridges of rock, called moraines, lining the landscape where glaciers once discarded them.

The ‘science’ gene

“When you’re young, you think you’re invincible,” said Putnam. Now the father of a 3-year-old, he’s aware of the dangers of exploring remote terrains. “You had to go over a number of very high passes to get to where you’re going,” he said of his many adventures. “It’s not like you just go back downhill.”

When there was Wi-Fi in the Himalayas, Whatsapp was his lifeline to his wife and baby. Nowadays, he looks forward to spending fewer than four months a year in the field in favor of his dad duties.

Putnam’s love of science runs in the family. His father, archaeologist David Putnam, took a college class with George Denton, who later became Putnam’s Ph.D. adviser. Putnam’s wife is a paleoceanographer and led research on a cruise off the Gulf of Maine in August.

“We’re trying to see if we can begin to plan our fieldwork in ways that we can do it together,” Putnam said. The climate science couple is considering Southern California for her research and New Zealand for his.

They haven’t been in the field together since Putnam’s wife visited him in New Zealand several years ago and he proposed on a peak of the Tasman Glacier.

“I was kind of a nervous wreck about the whole thing, like what if she says no?” Putnam said. She said yes, and they helicoptered back down to finish the day’s work.

Growing up in the Arctic Circle

When Putnam was in high school, his family spent a year in Utqiagvik (then called Barrow) in the northern tip of Alaska.

“We could see when the sea ice [or frozen ocean water] would come in and when it would leave,” Putnam said. The deep north first exposed him to how climate impacted people. The Inupiat people native to Alaska travel over sea ice to hunt and fish for food during the winter.

He celebrated his eighteenth birthday with his biology teacher in the Arctic Ocean on an icebreaker, a ship designed to cut through the ice sheets on the water. His mom snuck a birthday cake for him onto a helicopter during a supply run from the mainland.

“She had me thoroughly embarrassed,” Putnam said. “But that [trip] really clinched it for me; I knew somehow I wanted to get involved, I wanted to be a part of the climate science community.”

“There’s just some sort of intrinsic curiosity in trying to figure out how things work,” he said. “That’s what I find fun about it.”

Determined to continue developing glacier chronologies to advance climate research, Putnam is laying plans for next year’s field seasons – hopefully to Patagonia. His and others’ glacier chronologies demonstrate the complexity of dynamic global climate cycles documented across much of the past 1 million years. And yet, scientists agree that human-driven ice melt and climate change is eclipsing the speed at which climates changed in the past.

Photo at top: Glacier geologist and paleoclimate scientist Aaron Putnam, 40, snaps a photo of a boulder in Soda Lake, Wyoming, in July 2021. The Laurentide Ice Sheet covered the northern regions of the continent, including Wyoming, during the last ice age. The retreat of the ice sheet gouged out the Great Lakes we know today and filled them with meltwater. (Lauren Woods/UNIVERITY OF MAINE)

Poonam Narotam is a health, science, and environment reporter at Medill. You can follow her on Twitter at @namsorama.

Climate change threatens El Niño crop and rainfall boosts with severe disruptions

Climate change threatens El Niño crop and rainfall boosts with severe disruptions

By Carly Menker, Dec. 14, 2021 –

Columbia University Ph.D. student Celeste Pallone devotes her research time observing Eastern Equatorial Pacific dwelling planktonic foraminifera – very tiny creatures that can give huge clues into the pace of ocean climate change.

“Marine sediment cores act as an archive of sea surface temperatures, past environments, including past temperatures, and general environmental factors, such as past global ice volume,” she said of the single-celled, shelled organisms she studies at Columbia’s Lamont-Doherty Earth Observatory high in the Palisades outside New York City. “I examine these proxies, which can be biological or chemical or physical, and then using them I reconstruct oceanographic conditions in the past helping craft record of the El Niño-Southern Oscillation [ENSO].”

A washed and sorted marine sediment sample from the Eastern Equatorial Pacific, showing a tropical assemblage of foraminifera shells, which can be used to infer past sea surface temperatures, hydrology, and climatic variability. (Courtesy of Celeste Pallone)

Climate change threatens El Nino and other ages-old weather systems with severe disruptions. ENSO varies on 2–7 year timescales and has major influences on temperature, wind patterns, biological productivity and rainfall across the tropical Pacific and far beyond. This also includes crop yields, floods and droughts at multiple locations, said Jerry McManus, field researcher and professor at Columbia’s Department of Earth and Environmental Sciences and Lamont-Doherty. Understanding the baseline influences on this system is key to gauging how it may be altered through climate changes.

The latest report from the U.N.’s International Panel on Climate Change expresses continued uncertainty about how the El Niño-Southern Oscillation will respond to continued warming, although the consequences that play out in the global water cycle are likely to be greater (more rain and flooding in some areas, with increased drought in others). South American countries such as Peru rely on the periodic El Niño to bring warmer ocean waters and rainfall. The uncertainly over El Niño is unsettling. Additionally, the Special Report on the Ocean and Cryosphere in a Changing Climate projected that over the 21st century, the ocean will transition to unprecedented conditions with increased temperatures, further acidification and oxygen decline.  It predicts more frequent marine heatwaves along with extreme El Niño and La Niña events.

Pallone is seeing how she can reconstruct the oceanography of the eastern equatorial Pacific Ocean (the region of the open ocean directly south of Mexico and Central America) during a particularly interesting time in Earth’s past as she reported at the annual Comer Climate Conference, an international gathering hosted in southern Wisconsin but held virtually this fall.

According to WHO, the warming of the central to eastern tropical Pacific Ocean in the El Niño 2015-2016 event is affecting more than 60 million people, particularly in eastern and southern Africa, the Horn of Africa, Latin America and the Caribbean and the Asia-Pacific region.

El Niño is an oceanic climate pattern that characterizes unusual warming of surface waters in the eastern tropical Pacific Ocean. Considered the warm phase of a larger phenomenon called the El Niño-Southern Oscillation, the system marks a periodic warming of ocean surface temperatures. Its opposite, La Niña, is marked by an unusual cooling of oceanic surface temperatures. El Niño brings drier warmer weather to the northern United States and wetter conditions to the south. Arriving in the Americas around Christmas time in the cycle described below, it was given the name El Niño (meaning Little Boy or the Christ child) by Spanish fishermen.

Each climate pattern lasts about 9-12 months, and both tend to develop during the spring (March-June), reach peak intensity during the late autumn or winter (November-February) and then weaken during the spring or early summer (March-June) according to the National Oceanic and Atmospheric Administration.

“If you have a strong El Niño event, that might be followed by a strong La Niña event as well – but it is a consistent oscillation that we’ve observed,” Pallone said.

El Niño/La Niña’s hydrological effects are the most important implications on the human population. It can affect rainfall patterns impacting agriculture or even flooding and monsoonal seasons. With satellite measurements of sea surface temperature since the 1980s, there are historical records that indicate the same kind of variability that we observe today suggesting that the ENSO system has been occurring for certain at least the past several thousand years, perhaps even more.

“If we can kind of identify periods that had recurrent warming episodes, for example, or a really large range of temperature variability, we can associate those periods with stronger or more frequent El Niño events,” Pallone said.

McManus highlighted the importance of why Pallone chose to focus on a particular time period, Marine Isotope Stage 5. The marine isotope stages offer a way of tracking ice ages and the periods between them based on the oxygen isotopes found in sediment cores.

“MIS5 was approximately 130,000 to 70,000 years ago and the last interglacial interval that was subsequently followed by a major global ice age, and then the deglacial warming that led to the Holocene interglacial interval of the last 10 or 11 thousand years, the time when all of human agriculture and civilization has developed,” McManus said.

He emphasized that MIS5 is the interval of time when Earth was last as warm as it is today before the most recent ice age, offering the potential to provide insights into natural variability during a warm interval. “The 60,000 years of MIS5 were characterized by three large cycles in the seasonal distribution of sunlight based on the progression of the seasons around Earth’s elliptical orbit,” he said. This time period can help differentiate between natural climate events and what is going on now because of the climate similarities between the time periods of past and present.

Pallone received her undergraduate degree in environmental science at Barnard College. She earned an MA and is a current Ph.D. student in the Department of Earth and Environmental Sciences at Columbia University and the Lamont-Doherty Earth Observatory. She is a paleoceanographer and isotope geochemist with an interest in tropical dynamics during past glacial cycles. (Courtesy of Celeste Pallone)

Pallone’s research is tri-fold. She uses multiple methodologies to reconstruct the surface and subsurface oceanography of the eastern equatorial Pacific Ocean during a particularly interesting time in Earth’s past, according to McManus.

“She makes many measurements of the oxygen isotope ratios in individual specimens of surface-dwelling planktonic foraminifera shells preserved in deep-sea sediments deposited at that time to learn about the temperature each one experienced during its month or so lifetime, and to compare the range of temperatures that characterized different intervals in the past,” he said. “That tells us something about El Niño-Southern Oscillation (ENSO) variability.”

Another piece of her research is an analysis of multiple specimens of foraminifera species that live at a range of depths below the sea surface to assess their shells and biology as a way to assess where and how fast the temperature changes beneath the surface ocean, hallmarks of El Niño and La Niña events. She studies thermocline structure as another clue to temperature change. The thermocline is the transitional layer between warmer mixed water at the ocean’s surface and cooler deep water below.

Pallone also measures uranium, thorium and protactinium isotopes in the bulk sediment to estimate the amount of material that rained down due to biological productivity in the past.

“A shallower thermocline means that more nutrient-rich waters were moving toward the surface ocean at a particular time, potentially enhancing productivity,” McManus said.

Ultimately, by combining these three main methods, this enables Pallone to make a richer and more robust reconstruction of the ocean state in the EEP at different times throughout history.

The strength or frequency of an El Niño event can be influenced by small changes in Earth’s orbital geometry, with the main factor being changes in solar insulation that are driven by orbital shifts. Teleconnections, climate anomalies related to each other over long distances, also come into play because of how the atmosphere and oceans talk to each other.

“Because of the global circulation of the atmosphere in the ocean, if you have an event happening in the equatorial Pacific, for example, you’ll have effects in other parts of the world,” Pallone said.

Pallone started her research thinking that by using the foraminifera as a proxy and the MIS5 time period, she could create a good analog for modern warning.

“If we can reconstruct the environment during [MIS5], maybe it will inform about what changes could be coming in the future,” she said. “This, with most comparisons between the paleo record and the modern, we’re going to have kind of changes in temperature that might have been or that might be quicker than anything that we’ve seen in the past. But the past is still a useful analog for what could happen in the system.”

For the future, global efforts are needed to curb climate change. At the 2021 Glasgow Climate Conference, the United Nations called for a worldwide response to accelerate climate action to limit global temperature rise at a 1.5 degree C tipping point. The goal called for cutting global fossil fuel emissions by 45% compared to 2010 levels and doing so by 2030. The goal was not adopted.

Going forward, U.N. Secretary-General António Guterres deemed that the world is in emergency mode, meaning we must end fossil fuel subsidies, phase out coal, put a price on carbon, protect vulnerable communities, and deliver the $100 billion climate finance commitment.

Pallone’s research is a small but crucial step in reaching toward this goal.

El Niño events are the dominant source of like this kind of decades scale climate variability today,” Pallone said. “It’s unsettling that we’re not so confident in what could happen to them in the coming years or in the coming century.”

Photo at top: El Niño is anchored in the tropical Pacific, but it affects climate “downstream” in the United States. This shows the U.S. impacts of the climate patterns. (NOAA)

Carly Menker is a health, environment and science reporter for the Medill News Service and a Comer Scholar at Medill.  Follow her on Twitter @carlymenker.

COLDEX: The search for Earth’s oldest ice and new climate solutions

COLDEX: The search for Earth’s oldest ice and new climate solutions

By Christian Elliott, Dec. 9, 2021 –

Even summer days are cold in the Allan Hills Blue Ice Area, a meteorite-strewn expanse of glacier flanked by mountains at the eastern edge of the Antarctic ice sheet near the McMurdo Station research center.

Jeff Severinghaus, a paleoclimatologist at the Scripps Institute of Oceanography, and his colleagues at Princeton University discovered here in 2017 a 2.7-million-year-old chunk of glacial ice containing bubbles of trapped air from Earth’s ancient atmosphere.

That ice turned out to be contaminated by modern air, destroying its link to climate conditions millions of years ago. But the discovery reinvigorated the quest in the ice core science field to find the world’s oldest ice. Right now, the continuous record from a single ice core goes back only about 800,000 years.

Ed Brook operates a saw in Antarctica, slicing an ice core into smaller pieces. (Courtesy of Ed Brook)

In coming years, the world will be a much warmer place – average temperatures will increase by 2 to 3 degrees Celsius (3.6 to 5.4 degrees Fahrenheit), and arctic temperatures will rise by twice that rate. Over the next 10 years, paleoclimatologists hope to extend the ice core record back to 3 million years ago, when they know from climate clues in deep sea sediment cores that the Earth was last that warm. As the planet heats up today, many questions remain. How bad will hurricanes get? How frequent will forest fires become? How high will seas rise?

“The only practical way to know the answers to these questions is to get ice cores that are 3 million years old,” Severinghaus said. “It’s the only way to look into our future and see what we’re in for.”

Severinghaus has spent the last 25 years in Antarctica and in his lab in California studying the composition of gases in polar ice. Ice cores, he said, are key to understanding how Earth’s climate changes with varying levels of atmospheric carbon dioxide.

“There’s no other way to get a sample of the ancient atmosphere, other than the air bubbles in ice cores,” Severinghaus said. “From the ice cores, we learned that carbon dioxide concentrations have never been as high as they are today.”

The natural atmospheric carbon dioxide concentration over the last million or so years was 280 parts per million during warm spells and 180 parts per million during the cold snaps of ice ages. Today, CO2 levels hover at an unprecedented 420 parts per million due to human-generated fossil fuel emissions.

A new collaborative global effort is hot on the trail of the ancient ice, Severinghaus reported at the annual fall Comer Climate Conference, held virtually this year on Oct. 4-5.

COLDEX

Ed Brook, a paleoclimatologist at Oregon State University, received the good news in Februrary – the National Science Foundation selected his proposal for an ice-core-focused Science and Technology Center he calls COLDEX, the Center for Oldest Ice Exploration.

Over the prior two years, Brook brought together 30 of the nation’s leading paleoclimatologists representing 13 universities to jointly apply for the grant, which includes $25 million in funding over five years with a likely extension to 10 years and $50 million in total. Brook said the center represents the ice core field finally uniting a “critical mass” of researchers to justify such a massive investment in paleoclimate research.

Ed Brook presents COLDEX’s goals at the virtual Comer Conference on Oct. 4.

“It was so rewarding, because the right collaborators really stepped up and were interested in making this happen,” Brook said. “But it’s not for the faint of heart to try to organize this many people.”

As the Earth continues to warm, the race to find Antarctica’s oldest ice and understand historic climate change is accelerating – across the continent, the EU, Japan, Australia and Russia also are beginning multimillion-dollar drilling operations, and China’s effort has been underway, with slow progress, since 2012.

With its unprecedented level of funding, COLDEX’s explicit goal is to drill a single continuous deep ice core 1.5 million years old that is likely to be between 1.5 and 2 miles long and then extend the record back further to 3 million years through a composite of discontinuous “snippets” of ice from across the continent. Even though the Antarctic sheet is 2 miles thick in some places, it flows, melts and fractures over time, so researchers think 1.5 million years is the limit for a single core in one location. The oldest ice tends to exist in chunks at the windswept rocky edges of the sheet, like at the Allan Hills site.

“When you get back to 3 million years, there’s no ice that’s still intact stratigraphically – it’s all chopped up and mixed out of order, like a deck of cards that’s been shuffled,” said Severinghaus, who’s a co-principal investigator on COLDEX.

“These patches are out there,” Brook said. “But we don’t know exactly where they are or how many of them there are.”

Severinghaus compares reconstructing the ice core record to an archaeologist reassembling pieces of broken pottery to build a whole. Thanks to advances in geochemistry – paleoclimatologists can now study ancient atmospheric changes using argon, nitrogen, krypton and xenon isotopes in addition to the less accurate oxygen isotopes used in the 1970s – and the fact that atmospheric gas composition is the same throughout the world at any given point in time, COLDEX researchers can put together hundreds of puzzle pieces of ice from across Antarctica in the correct historical order.

McMurdo Station (USAP South Pole Webcam)

“We’re pretty confident we can construct a continuous composite record of the ancient atmosphere,” Severinghaus said. “It’s just going to be a bit of detective work.”

Drilling the 1.5-million-year-old deep ice core might prove just as challenging. Drilling ice cores is a slow, expensive process that requires heavy equipment. Researchers must travel inland, far from McMurdo Station, and establish a base camp where they’ll live and work for the season, which lasts the austral summer – October to February – when the sun never sets. During the winter, temperatures sink to -50 degrees Celsius (-58 degrees Fahrenheit), and the continent plunges into continuous darkness.

“It’s like being at sea,” Brook said. “There’s nothing to see except for snow. And it’s cold. The work is hard.”

Drilling rigs cut through the ice sheet a few meters at a time, and researchers hoist out heavy sections of core as the drill descends. It’s a slow, repetitive process. A 3,000-meter core (more than 1.8 miles) could take up to three seasons – three years – to complete.

The challenge, then, is to find an inland site with deep and old enough ice to justify setting up the COLDEX drilling camp. But much of the deep interior of the Antarctic ice sheet where that old ice likely is has never been mapped – scientists don’t know how deep the ice is.

“It’s just a blank spot on the map,” Severinghaus said. “So, we’re doing basic exploration at this point.”

The first five years

The COLDEX initiative kicked off in earnest in September. Brook is currently hiring researchers, coordinating with NSF logistics contractors to organize trips to Antarctica and building websites and lab spaces. Initial fieldwork – including testing a new fast thermal melt probe called Ice Diver in Greenland – is set to begin in 2022.

A staff member retrieves an ice core at the National Ice Core Lab in Denver, Colorado. (NSF NICL)

While some scientists – including Severinghaus and the Princeton team – continue searching for chunks of old ice at the ice sheet’s fringes and drill rapid 100-meter shallow cores there using Severinghaus’ Rapid Access Ice Drill, others will begin reconnaissance work to find the best site for the 1.5-million-year-old core.

“We’re going to be doing airborne radar echo sounding with new technology in a broad region from the South Pole towards Dome A,” an ice coring site, Brook said. “We’re looking to gather data that would help us put teams on the ground to do detailed radar in specific locations.”

Antarctic “domes” are the highest points on the ice sheet – locations where steady snowfall piled up over thousands of years to create particularly thick ice ideal for drilling old cores. A European team extracted the 800,000-year-old record core in 2013 at Dome C. Japan plans to drill for a 1.5-million-year-old core at Dome Fuji, Russia at Dome B, and Europe and Australia at Dome C.

Recent advances in aerial ground-penetrating radar make it possible for scientists to detect the thickness of the ice sheet as well as layers of dust impurities that indicate colder versus warmer periods – and thus the relative age of the ice. Ground teams will then follow up at two candidate sites with the Ice Diver reconnaissance drill, which can date ice quickly using a laser that detects dust variations, to narrow the choice down to one site.

“We want to know before we get into the $50 million logistics of drilling a deep ice core that the target ice is really there,” Severinghaus said.

The second five-year period will be dedicated to drilling and extracting that 1.5-million-year-old deep ice core and sharing it with the entire field for data analysis.

That core will also help scientists answer the mystery of the Mid-Pleistocene Transition. Around 1.2 million years ago, the length of the transition between cold and warm climate periods abruptly shifted from 41,000 to 100,000 years. Scientists think changes in atmospheric carbon dioxide were to blame, but an older core would provide proof.

Diversifying polar science

COLDEX has another priority as well. As of 2020, only 10% of doctoral degrees in geoscience went to people of color. Faculty of color only hold 3.8% of tenure-track geoscience department positions. It’s a continuing problem, and one that’s received repeated coverage in the journal Nature in recent years.

“Earth science has a diversity problem.” Brook said. “Some other fields have made progress, but that’s just not true in the earth sciences. And polar science is near the worst end of that spectrum, at least anecdotally. The exploration of Antarctica and Greenland has been perceived as a white male thing for quite a while.”

Ed Brook works on ice core gas extraction equipment in his lab at Oregon State University. (Courtesy of Ed Brook)

That’s where the second half of COLDEX comes in – diversifying the ice core field by establishing partnerships with a variety of minority-serving organizations to combat stereotypes and form new pipelines into the field and directly into COLDEX research work over the next 10 years.

“So, it’s only half about finding the oldest ice on the planet.” Severinghaus said. “The other half is doing public facing diversity, equity, inclusion and outreach.”

For example, in the past 40 years, only 20 Native American women earned geosciences doctorates. Sarah Aarons, a paleoclimatologist and Alaska Native at Scripps, will lead a partnership with the Alaska Native Science and Engineering Program to recruit Alaska Native students into the geosciences and, through the NSF’s Research Experiences for Undergraduates program, involve them directly in COLDEX.

“We know the climate is changing twice as fast in the Arctic, and so having Alaska Native people who are experts in climate and the environment in positions in academia or government who know what’s happening in the region they’re from is really, really important,” Aarons said.

Stereotype inoculation theory states that people tend to choose to mentor other people who come from a similar racial or ethnic background or share lived experiences. With the polar sciences dominated by white male researchers, that’s a problem for recruiting new students.

“So, we also plan to do work within our own community to try to understand what kinds of biases we may have and how to overcome those and make our community more welcoming,” Brook said.

“The exciting thing about COLDEX is it’s bringing together a group of people from a really wide variety of research backgrounds into the same room who are all committed to the same goal – finding the oldest continuous ice core record – and combining our expertise to tackle that question,” Aarons said.

In November, world leaders gathered in Glasgow for the UN’s COP26 climate change conference. They were shown a vial of air from 1765, the beginning of the industrial revolution, extracted from Antarctic ice and a section of an ice core, ancient air bubbles slowly, audibly popping as it melted away in front of them. It was a powerful and urgent illustration of both polar ice’s fragility and its ability to describe our ancient atmosphere – where we’ve been and where we’re headed. Through COLDEX, our nation’s paleoclimatologists hope to provide the clearest picture yet.

Photo at top: Jeff Severinghaus (L) and fellow COLDEX participant John Goodge hold an ice and rock core recovered during a test of rapid drilling equipment designed for ancient ice reconnaissance. (Courtesy of Jeff Severinghaus)

Christian Elliott is a science and environmental reporter at Medill. You can follow him on Twitter at @csbelliott.

Into the unknown: Exploring caves to uncover climate change clues

Into the unknown: Exploring caves to uncover climate change clues

By Christian Elliott and Brittany Edelmann, Dec. 8, 2021 –

Nearly 20 years ago, then Ph.D. student Gina Moseley walked into a bar in Bristol to meet fellow members of the University of Bristol Spelæological Society caving club. An older caver talked with her over drinks about some small caves in northeastern Greenland he’d always dreamed of organizing an expedition to explore. But, “logistically, it’s a nightmare to get out there,” said Moseley, now a professor in the Institute of Geology at the University of Innsbruck in Austria. The caver gave her all the papers he’d collected on the caves, and for years she kept them filed away.

Much later, a 1960 article by U.S. military geologists among the papers caught her eye. In their search for prime airfield locations, the geologists discovered caves with interesting geological features — crystalline calcite, stalagmites and flowstone deposits. To Moseley, that was proof Greenland’s caves contained something critical to scientists’ understanding of Earth’s ancient climate.

Moseley took her first steps into caving years earlier with her mom on a holiday trip when she was 12. She loved it. As she started grad school in Bristol, she discovered she could bring together her fascination with caves and her interest in studying paleoclimate to understand how future climate change — pushed by fossil fuel emissions of human activities — will affect the Earth.

Caves are normally “not altered or impacted by other processes” and “they’re so well-preserved over thousands of years,” Moseley said. That makes them a great location for climate research and creating records that can function as important analogs for future climate change.

The 2021 Comer Climate Conference on Oct. 4 – 5 brought together scientists from around the world, including Moseley and fellow paleoclimate researcher Kathleen Wendt.

Devil’s Hole

“Devils Hole was where it all began. That was the start of cave paleoclimate research,” Moseley said. Paleoclimate scientists first rappelled down into the deep, narrow cave in the Amargosa Desert in southwest Nevada in the late 1980s.

Using cores of the thick calcite crusts on the cave walls, which accumulated steadily over time, researchers reconstructed 500,000 years of climate history here with Uranium-thorium dating. Uranium-thorium dating provides insight into when a rock was formed– giving a date to the origin of the rock.

Devil’s Hole was also where Moseley and Wendt, who has her Ph.D. from the University of Innsbruck in Austria, got their start in cave paleoclimate science. In 2017, they returned to Devils Hole to extend the climate record further and validate the older results.

In their research Moseley and Wendt focused on oxygen isotopes, which provide temperature information about historic temperatures. During ice ages, a heavier isotope of oxygen forms at higher levels than during warm spells.

Wendt is getting ready to submit a new paper on the oxygen isotope record from Devils Hole. By showing the fluctuation in types of isotopes, heavier versus lighter forms of oxygen, this will give “clues into changes in temperature and a little bit about the source of precipitation over time,” Wendt said.

They found the water table dropped below modern levels during the last interglacial, 120,000 years ago, when Earth’s orbit brought the planet closer to the sun. That time period is an analog for southern Nevada’s hotter and drier future that will be accelerated beyond natural planetary fluctuations with human-forced extremes of climate change.

“Studying the paleoclimate tells us what nature is capable of,” Wendt said.

The Greenland caves

Paleoclimatologists who focus on caves often study speleothems — mineral deposits formed by dripping water. Protected within caves from the elements, these dripstones (stalagmites and stalactites) and flowstones grow as layers of calcium carbonate carried by rainwater add up over hundreds of thousands of years.

One of the flowstones Moseley found in the caves was specifically mentioned in the 1960 paper that inspired the expedition.

In Greenland, now a rainless polar desert, speleothems formed during a time when the island’s climate was warmer and wetter. By collecting and sampling speleothems, Moseley can reconstruct that ancient climate period as an analog for the future, when Greenland will once again be warmer and wetter.

Over millions of years due to orbital changes, Earth’s climate alternates between warm and cold periods — interglacials and ice ages called glacials. Paleoclimatologists rely on air bubbles in cores taken from ice sheets in Greenland and the Antarctic to study the composition of the ancient climate’s atmosphere, but there’s a problem — during warm periods, the ice sheet melts. That’s where the caves come in.

“So the caves offer the polar opposite of what the ice cores do because the ice cores tend to be cold-based climate records and the caves can give us warm-based climate records. So, we get to the two different parts together,” Moseley said.

That’s a common theme in paleoclimatology — no one climate proxy shows the big picture. To fully understand Earth’s ancient climate, scientists must piece together hundreds of pieces from data from sources across the world.

“If you have one cave in one location, that’s kind of interesting. But if you can relate that to other caves in other locations, ice cores in other locations, deep sea sediments in other locations and get the whole picture, that’s where it really gets interesting. That’s where we can answer the big questions and tackle the big issues,” Moseley said.

As the Arctic continues to warm at twice the rate of the rest of the world, understanding what warm and wet historic climate periods were like can help scientists know what to expert in the imminent future.

This leads to Moseley’s next adventure in 2023, where she will explore completely untouched caves in Northern Greenland. This was only made possible with an award from Rolex — which provides funding for such an endeavor.

Christian Elliott and Brittany Edelmann are science and environmental reporters at Medill. You can follow them on Twitter at @csbelliott. and @brittedelmann.

Climate change pushes precipitation — and ability to predict it — to its limits

Climate change pushes precipitation — and ability to predict it — to its limits

By Sarah Anderson, Dec. 7, 2021 –

Primed by a drought that has lasted longer than the 1930s Dust Bowl, wildfires scorched over 5 million acres of land in the western United States this year. The water level of Lake Powell is dipping dangerously low amid the severe dry spell, threatening the hydroelectric power it generates.

On the other side of the country, a record-breaking 2020 hurricane season produced so many tropical storms that the list of 21 names for them had to be supplemented with Greek alphabet letters for just the second time in history. Hurricane Laura alone caused 42 deaths and almost $20 billion in flood damage.

Climate change is pushing precipitation to both extremes. The elevated annual mean temperature in the United States is accompanied by higher levels of rain and snow in the eastern, southeastern and midwestern regions of the country and decreases in precipitation in the western and southwestern areas, according to the National Oceanic and Atmospheric Administration (NOAA).

“The basic result is that we (will) see more floods and more droughts,” said Richard Alley, a climate scientist and professor of geosciences at Pennsylvania State University, during the annual 2021 Comer Climate Conference, held virtually this year. “You get more intense events in a warmer world.”

As the annual mean temperature increases across the United States, precipitation concentrates in certain regions. (Image source: NOAA)

 

Climate change has heightened the need to predict and prepare for extreme precipitation events, but it has also impaired the ability to do so. According to NOAA, the United States’ average seasonal precipitation skill — the accuracy in forecasting the amount of precipitation over an upcoming season in a specific region — has declined in recent years.

Precipitation skill varies for different areas, in part because naturally occurring cycles in ocean temperature have a well-documented effect on precipitation trends. El Niño, a climate phenomenon resulting from a warming of the central and eastern Pacific Ocean that occurs every three to seven years on average, has a consistent impact on rainfall in the places along its path each time it strikes.

Seasonal precipitation skill is “actually pretty good in places that are affected by El Niño because we can predict El Niño, and El Niño statistically affects weather patterns,” said David Battisti, a professor of atmospheric sciences at the University of Washington.

The U.S. seasonal precipitation skill has deteriorated since 2013. (Image source: NOAA)

Elsewhere, however, technology has struggled to keep up with new variables as the climate evolves. The impact of climate change on precipitation — and precipitation skill — can be largely traced to the ocean, which stores approximately 93% of excess heat driven by emissions from fossil fuel use, according to the Intergovernmental Panel on Climate Change.

“If you heat the planet, you get more evaporation from the ocean, just like if you heat a pan on your stove, you start to get steam coming off of it,” Battisti said. The additional water vapor in the air means when conditions are right for rain, it rains harder.

As the relationship between rising ocean temperatures and precipitation became clear, the U.S. National Weather Service realized it needed to incorporate ocean processes into its forecasts, said Joellen Russell, a climate scientist and oceanographer at the University of Arizona, at the Comer Climate Conference. However, rather than developing a new climate model that integrated ocean from the start, the ocean element was tacked onto the existing atmosphere component.

“They coupled it, but it wasn’t really designed to be coupled,” Russell said, resulting in a weather simulation that cannot account for the full network of interactions between ocean and atmosphere. It more closely resembles a layer of red painted over a layer of blue than a pointillist blending of red and blue dots that appears purple.

The accuracy of U.S. precipitation prediction tools is also limited by the lack of information on ocean conditions due to shortcomings in operational oceanography, Russell said. For example, orbital satellites often sample from confined and redundant areas, collecting spotty real-time data to feed into the model.

While some scientists focus on how to gather and use current data to further improve seasonal precipitation skill, other researchers are looking to the past to predict the long-term impacts of climate change on precipitation in specific regions. Dylan Parmenter, a Ph.D. student in the Department of Earth and Environmental Sciences at the University of Minnesota, presented his work studying the chemical composition of stalagmites to reconstruct rainfall patterns in the Amazon at the Comer Climate Conference.

Dylan Parmenter collects a cross section of stalagmite from a cave, which shows tree ring-like features corresponding to different time points. (Images courtesy of Dylan Parmenter)

Stalagmites form when water vapor carried from the ocean combines with the soil at a cave site and drips onto the floor of the cave. In this way, “stalagmites are kind of like fossilized precipitation,” Parmenter said. The oxygen atoms in the water vapor exist as two versions — one heavier and one lighter. If it rains as the water vapor cloud travels, the heavier oxygen atoms fall to the ground with the rain before reaching the cave. By measuring the ratio of the two types of oxygen in a sample of stalagmite, Parmenter can estimate the precipitation conditions when the stalagmite was created. To determine the age of the sample, he measures to what extent uranium atoms in the stalagmite have decayed, expelling some of their subatomic particles.

These ancient rainfall records can help scientists understand the effect of past climate patterns on precipitation, providing a useful reference point when predicting the impact of modern climate change.

“If we want to know how precipitation in a certain region is going to change from climate change, there’s nothing to compare that to,” Parmenter said. “Our work is going back and saying: With these natural climate change processes in the past, how did it react?”

While Russell acknowledges there is no time in history perfectly representative of the current climate conditions, the fundamental insight gained from research like Parmenter’s will be critical in informing responses to climate change.

“We are in the undiscovered country of the future, as Shakespeare put it. So, no, it’s not going to be exactly the same as any previous (time),” she said. “But being able to look at how these mechanisms have worked in the past can help us accelerate the learning that is going to be required to do the preventing, the mitigating and the adapting.”

Featured photo at top: A satellite image captures Hurricane Laura’s landfall. (Image source: NOAA)

Sarah Anderson is a health, environment and science reporter at Medill and a Ph.D. chemist.  Follow her on Twitter @seanderson63.

Enhanced weathering: When climate research takes unexpected turns

Enhanced weathering: When climate research takes unexpected turns

By Brittany Edelmann and Carly Menker, Dec. 5, 2021 –

Oxford University Ph.D. student Frankie Buckingham collected the 30, 1-meter-long cylindrical tubes of soil she needed for climate research in August 2018 on a British farm in North Oxfordshire. The farm had previously cultivated oats and barley in the soil. A variety of crushed rocks and minerals, such as basalt, olivine and volcanic ash, were added to the 30 cores and then positioned on the roof of Oxford’s Earth Sciences Department building. From October 2018 to June 2021, Buckingham analyzed the soils to watch for the effects of enhanced weathering on climate change impacts. But, what she found wasn’t quite what she expected.

Buckingham’s study focused on “enhanced weathering” as a carbon dioxide removal technique involving the application of crushed rock to agricultural soil.

Carbon dioxide in the atmosphere is a thermostat for climate change, holding in heat that drives global warming and driving changes in our climate as we know it. Carbon dioxide levels today are more than 35% higher than at any point in at least the past 800,000 years and rose 30% just since 1970. The last time the atmospheric CO2 levels matched today’s concentrations was over 3 million years ago, during the Mid-Pliocene Warm Period. Temperatures then ranged from 2 degrees to 3 degrees Celsius (3.6 degrees to 5.4 degrees Fahrenheit) higher than during the pre-industrial era and sea level leveled off at 15 to 25 meters (50 to 80 feet) higher than today, according to the National Oceanic and Atmospheric Administration (NOAA).

Enhanced weathering is a process that aims to accelerate natural silicate weathering during which carbon dioxide reacts with rocks, a process that usually takes millions of years. Silicate weathering begins with the reaction between water, carbon dioxide and silicate rocks, which breaks down the rock. Eventually, the dissolved components are washed into the ocean where the carbon is stored for hundreds of thousands of years, either as mineral sediments or dissolved in the water, according to Buckingham. Enhanced weathering amps up this process by breaking down silicate rocks, such as basalt, into tiny pieces in a way of skipping slow weathering processes. The powder made from this is spread on agricultural land and the process can be further accelerated by fungi and roots in the soil.

Buckingham, on the roof of her research building, extracts water from the soil cores for further analysis of enhanced weathering processes. (Photo credit: Frankie Buckingham)

As a young child, Buckingham was already interested in climate change. She obtained a master’s degree in Earth Sciences from the University of Oxford, focusing on past periods of climate change and studying cave deposits.  During her Ph.D. program, she switched gears to try to answer the question of “how we might be able to prevent rising global temperatures?”

“The emergency of the climate crisis makes it a thrilling area to work in,” Buckingham said.

Buckingham started her presentation about her research at the 2021 Comer Climate Conference talking about The Paris Agreement, an international treaty pledging to limit greenhouse gas emissions so that the average global temperature rise is kept under 2 degrees Celsius and preferably under 1.5 degrees. Despite having already sparked low-carbon solutions and new markets, there are still many actions that need to be implemented, one of them being negative emission technologies to help remove carbon dioxide from the atmosphere. This is where enhanced weathering comes in.

Buckingham’s results so far focus strictly on crushed basalt instead of crushed olivine, which most researchers have used. Why has research favored olivine? It has been shown to dissolve the quickest, absorbing CO2 in the process, Buckingham said. But further research indicated that olivine releases harmful chromium and nickel into the soils, something that takes a toll on the environment.

Assumptions made from previous research using simple experiments conducted in the laboratory – beaker experiments – gave a more optimistic view of the weathering process, Buckingham said. Her research differed because it was conducted in a way that was “as close to the field (as) you can get.”

Buckingham explained findings on why some mineral treatments dissolve quicker. She connected her field research back to beaker research with olivine, which revealed that olivine is one of the mineral that dissolves the quickest. Contrary to original expectations, Buckingham’s research showed crushed basalt actually dissolves three to four orders slower than previously expected.

Buckingham cuts soil core into 10-centimeter segments and measures for different physical properties. (Photo credit: Frankie Buckingham)

She elaborated on how many current enhanced weathering calculations assume that basalt can be applied to crops year after year – safely compared with olivine – and that it will dissolve. But, when looking at the crushed basalt in the soil cores, her research revealed that 99% of the crushed basalt does not dissolve.

“Within 50 years, you will have 25 centimeters (10 inches) of a basalt layer,” Buckingham said, which can affect agriculture and farmers who use the crushed basalt in their soil.

Previous thinking also expected the dissolution products (the components that separated from the rock) to travel from the soil into the oceans to help stem ocean acidification and increase the pH content within the ocean water. By consuming acidic ions during dissolution and by releasing important ions such as calcium and magnesium,  enhanced weathering sequesters CO2  and helps counteract ocean acidification.

But, Buckingham found that the “dissolution products were retained in the core.”

“The dissolution products can be sticky and can be chemically removed from the water,” Buckingham said, which prevents the dissolution products from getting into the oceans.

Negative emission technologies

Enhanced weathering is one type of negative emission technology to remove CO2 from the environment. And, as Buckingham’s research shows, more than one process is needed to have an impact on the pace at which the world generates CO2 emissions from fossil fuel use. There are “a plethora of negative emissions technologies” to help combat climate change, according to Buckingham. We cannot rely on just one, she said.

Some other examples include planting new trees, biochar, ocean alkalinization and bioenergy carbon capture and storage. Mature trees don’t sequester carbon dioxide as quickly, so this is where young trees come in to help. Organic material is burned into biochar, which then locks up the carbon. Ocean alkalinization can help to draw down carbon dioxide by spreading alkaline crushed rocks directly into oceans, which ultimately will raise the alkalinity of the ocean water. Bioenergy with carbon capture and storage (BECCS) is a process where biomass, such as crops or wood, that sequester carbon dioxide when grown, are burned for heat and electricity. The carbon dioxide emitted during burning is captured and transported for underground storage.

Where do we go from here?

Buckingham emphasized how her research shows that enhanced weathering may not draw down as much carbon dioxide as previously anticipated and can have “major impacts to soil chemistry.” But “that’s not a reason to lose hope,” she said. Her research was done in the U.K., as opposed to a warmer, more humid climate like the tropics. In tropical climates, more CO2 is drawn out faster due to the quicker breakdown of crushed rock and minerals.

Research is done to figure out answers to questions. The hope is that positive findings result, she said.

This research showed different results from previous assumptions. Jeff Servinghaus, professor of Geosciences at the Scripps Institution of Oceanography at the University of California, San Diego, expressed gratitude to Buckingham at the conference.

“It’s very important work, because you know if we chase down dead ends, that’s just wasted time and money, right? So thank you for that,” he said

Geologist Richard Alley, emcee of the Comer Conference and a geosciences professor at Pennsylvania State University, said the more research that is done, the clearer it is that it’s easier to keep carbon dioxide out of the air than taking it out.

“If you can enrich your soil that’s good and if you can take a little carbon dioxide down that’s great, but don’t count on that to solve the problem,” Alley said.

“And although this might sound quite negative, it highlights the more realistic situation that we need to be aware of,” Buckingham said.

Brittany Edelmann is a registered nurse. She is health, environment and science reporter and a Comer Scholar at Medill. Follow her on twitter @brittedelmann

Carly Menker is a health, environment and science reporter for the Medill News Service and a Comer Scholar at Medill.  Follow her on Twitter @carlymenker.

Melting tropical glaciers threaten freshwater sources while sea ice melt accelerates rising oceans

Melting tropical glaciers threaten freshwater sources while sea ice melt accelerates rising oceans

By Sarah Anderson, Nov. 16, 2021

“Tropical glacier” —  the term sounds like an oxymoron and, due to climate change, it might become one.

These bodies of ice nestle in the mountain ranges of tropical regions, providing a major source of freshwater and tourism revenue. But studies predict most tropical glaciers will disappear within the next 10 years taking critical water resources with them.

“It’s hugely important to understand the rate at which these glaciers are melting,” said Alice Doughty, a lecturer of Earth and climate sciences at the University of Maine.

Doughty and Meredith Kelly, a professor of Earth sciences at Dartmouth College, are developing a model to investigate tropical glacier melt in places such as the Rwenzori Mountains in Uganda and the Sierra Nevada del Cocuy in Colombia. They presented their findings at the virtual 2021 Comer Climate Conference, an annual event usually held in southwestern Wisconsin.

Glaciers sand down the rock beneath them as they melt, acting “sort of like bulldozers,” Kelly said. The debris piles up, depositing a series of ridge-like features called moraines at the glacier’s retreating boundaries. Kelly examines satellite images of a glacier site to identify moraines the glacier left behind, then analyzes samples of rock to determine when the moraines were created. By measuring a type of beryllium atom that accumulates in the rock as it is exposed to Earth’s atmosphere, Kelly can approximate how long ago the rock was freed from the ice’s hold to form the moraine. Collectively, this information allows her to generate a map of the size and shape of the glacier at a specific time in the past.

Moraines in the Sierra Nevada del Cocuy photographed by satellites (left- map and data courtesy of Jordan Herbert, M.S. student at Dartmouth College) and on the ground (right- image courtesy of Gordon Bromley, professor at the University of Maine).

 

Doughty then works to develop a computer model to simulate how climate variables interact to produce the glacier. She tries to “grow the glacier,” adjusting temperature, precipitation and other inputs until the glacier output matches Kelly’s map.

Data from any nearby weather stations provide a useful starting point; observing whether current climate conditions yield the modern glacier helps her evaluate the model. When the simulation is optimized, Kelly and Doughty will be able to use it to predict the effect of climate change on glacial melt.

“Once we calibrate the model, we can just as easily make things warmer,” Doughty said. “And so we can have estimates like in the Rwenzori, one degree of warming and those glaciers are gone.”

Other scientists are interested in developing similar models for the melting of sea ice, “a really big part of the climate system,” said Ed Brook, a professor of Earth, ocean and atmospheric sciences at Oregon State University.

Sea ice helps insulate the ocean from heat and gases in the atmosphere and contributes to sea level rise when it melts, but it doesn’t leave behind the same physical record as glaciers. While seasonal sea ice melting can be tracked using IP25, an organic molecule produced by algae that grow along the receding ice edge, the presence of permanent sea ice in the past has remained elusive.

“We don’t have a very good method for reconstructing how much sea ice there was at any particular time,” Brook said.

Frank Pavia is analyzing chunks of Arctic Ocean floor gathered in the mid-1990s, but he has journeyed to other ice-covered seas to collect similar samples. (Image courtesy of Frank Pavia)

Frank Pavia, a postdoctoral researcher in geological and planetary sciences at the California Institute of Technology, presented his research at the Comer Climate Conference, exploring a new way to monitor this more stable sea ice cover. His method relies on interplanetary dust particles, the solar system’s version of dust that rains down on Earth from outer space.

Interplanetary dust particles deposit a light type of helium atom onto the sea floor. If the surface of the ocean is blocked by ice, however, the particles (and the helium) can’t enter the water. Pavia is examining whether the amount of helium in the ocean floor can be used as a measure of sea ice cover. To account for any differences in helium levels due to changes in how fast atoms settle to the sea floor, he also measures a special thorium atom that is produced inside the ocean and sinks to the bottom at a constant rate, regardless of ice cover.

To test his method, Pavia acquired samples of the floor of the Arctic Ocean from the Last Glacial Maximum, one period of well-characterized sea ice cover in the Arctic. The age of the samples had been previously determined by measuring a radioactive form of carbon in the shells of tiny marine organisms that indicates when they were alive.

When sea ice cover was thick, Pavia detected high amounts of thorium but low levels of helium, demonstrating that while atoms were efficiently burying in the sea floor, helium couldn’t access the ocean due to the sea ice. When there was no sea ice cover, he measured similar signals for both thorium and helium, revealing that the helium atoms were successfully deposited into the ice-free ocean. Pavia is also interested in seeing if the period of melting in between gives a surge in helium, corresponding to an influx of interplanetary dust particles that accumulated on top of the ice over time.

While accurate measurements will require that the dust particles are evenly distributed in the ocean floor rather than concentrated in specific pockets, the approach “has a lot of promise,” Brook said. The prospect of detecting nonseasonal sea ice melting — an event that leaves very few fingerprints — via a helium spike could be a major advantage of the method, he said.

“It’s potentially very important, because if the pulse of particles was the signature of melting a bunch of permanent ice, then you would have a sign of that process, which would be very hard to see other ways,” Brook said.

After further validation, Pavia plans to use his method to reconstruct poorly understood sea ice patterns during past periods of warming in the Arctic. Like Kelly, he aims to provide a map that other researchers can use to test and refine models that simulate sea ice melting as climate change progresses.

“The hope is to help improve the projections of sea ice coverage into the future in the Arctic,” Pavia said.

Featured photo at top: Meredith Kelly and Alice Doughty study the pace of melting of tropical glaciers like this one in Uganda’s Rwenzori Mountains. (Image courtesy of Alice Doughty)

Sarah Anderson is a health, environment and science reporter at Medill and a Ph.D. chemist.  Follow her on Twitter @seanderson63.

Climate change continues as a global crisis amid COVID-19—and it’s the greater threat

Climate change continues as a global crisis amid COVID-19—and it’s the greater threat

By Shivani Majmudar, Dec. 18, 2020 –

COVID-19 swept the world, with little regard for anyone who stood in its path. Within weeks, the virus killed thousands, isolated people in their homes and sent economies plummeting.

Not only did COVID-19 overwhelm the United States health care system during the first surge, but our political leaders failed to mobilize alongside health experts to combat the virus together.

Consequently, the pandemic rages on. Today, almost nine months after the first reported coronavirus case in the U.S., more than 220,000 people have died.

“We are the richest country in the world. We have all this knowledge and capability, but it didn’t matter because we did not have trust,” said Joellen Russell, a professor of biogeochemical dynamics at the University of Arizona.

Without serious reform, environmental scientists at the 2020 Comer Climate Conference fear we are risking the same mistakes again with the far greater global threat of climate change.

Climate change impacts have accelerated in recent years, triggering more frequent and severe hurricanes, wildfires and heat waves. Conference attendees shared the concern that the heightened mistrust between scientists and many political leaders adds yet another barrier to effective legislative action and renders our communities increasingly vulnerable to the rapidly changing environment.

“Climate change is the pandemic without a vaccine,” said Raymond Pierrehumbert, a professor of physics at the University of Oxford. While biological innovation, including an expected vaccine, will bring COVID-19 under control, scientific knowledge alone cannot slow climate change. We have to act together and we have to act now, he added.

Failure to take collective action quickly may have been the biggest U.S. mistake in limiting the spread of the pandemic. The Trump Administration did not consider the virus as a serious threat until two months after the first COVID-19 case was reported. President Donald Trump left individual states to create their own stay-at-home protocols, which was why some reopened too early. He continues to undermine the recommended health guidelines of wearing face masks and social distancing. As a result, COVID-19 cases continue to surge at over 300,000 new infections on Dec. 17, with deaths hovering above 3,200 that day.

But this surge was not the case everywhere. For example, New Zealand championed rigorous prevention during the first outbreak and effectively curbed the spread of the virus.

“Science won,” said Russell, describing how New Zealand beat COVID-19. “People worked together. It requires a combination of willingness, leadership and science.”

Russell and other conference scientists urged that this balance be emulated around the world, starting with the U.S., to stem climate change. They presented their latest findings on melting glaciers linked to sea level rise and shifting wind and rain patterns, which can mean severe drought and crop failures. Delaying action can be disastrous, as seen with the pandemic, and the consequences of climate change are predicted to be even worse.

The Finite Volume Cubed-Sphere dynamical core (FV3) model is the newest global weather prediction model, designed to be more comprehensive of Earth’s systems. Previous weather models only accounted for the atmosphere, whereas the FV3 also includes oceans, ecosystems and dynamic vegetation. (Shivani Majmudar/MEDILL)

With global warming tied to fossil fuel emissions, conference scientists pointed to melting snow caps in the Himalayas depleting freshwater resources that over 1.9 billion people across Asia rely on. The warming climate is creating more dangerous outdoor working conditions in heat millions of workers can’t afford to avoid. Humans meddling with the ecosystem also drives the spread of pathogens and creates new vectors for the transmission of viruses from animals to people, such as COVID-19. A recent report from the United Nations Environment Programme and International Livestock Research Institute suggests that continued disruption of wildlife and the environment will make large disease outbreaks like COVID-19 more common. Closer to home, California and large swatches of the country are facing drought while the Midwest floods due to extreme rainfall.

As the world manages its reaction to this global crisis and prepares for the larger one at hand, scientists at the Comer Climate Conference identified two important lessons to be learned from the COVID-19 pandemic to help mitigate the imminent effects of climate change.

First, they called for added urgency to recognize the impact of carbon emissions and offer real-time updates to hold countries accountable for their energy policies that release greenhouse gases. Russell said without this transparency to encourage reform, climate change seems like a “big, endless problem instead of an immediate fight for our grandchildren’s future.”

Second, identify practical solutions. Many people oppose environmental reform out of fear that the economy will collapse even further, heightening the pressures of the pandemic. But veteran geoscientist Richard Alley argues that the shift to clean energy can actually stimulate the economy when viewed as an opportunity for political and technological innovation. Alley, a professor at Pennsylvania State University, was one of the founding mentors of the Comer Family Foundation’s support for climate research and fellowships. He sees energy innovation as a win-win for economic growth, human health, national security and the environment.

“We need to make energy something that is flexible and interactive so that people can use it in the way that is best for them,” Alley said. He suggested turning the electric grid into something like the internet, a platform on which people can buy, sell, and trade shares of resources. This way more people could access the financial and environmental benefits of clean energy without having to worry about investing in the individual resources for their properties.

Alley proposed a hypothetical example of a dairy farmer, struggling to stay afloat due to high costs of operation. Rather than paying for and installing a few solar panels for his roof, the farmer instead could invest in community solar, a power plant whose electricity is shared by multiple properties. The community grid sells solar electric power to homeowners who now no longer need to invest in their own solar panels. It’s cost-effective, and gives the farmer a greater chance at survival because now he has two crops—milk and energy—instead of just one.

In other words, instead of funding policies and lobbies to decide who gets to control our resources, we should be financing ways to make more efficient use of our resources, Alley said.

Solutions like this require a multidisciplinary team of scientists, engineers and economists. At the core of these efforts, however, lies the country’s leadership. Now, more than ever before, we need an administration who will provide a science-backed, coordinated response to climate change while prioritizing the well-being of its citizens.

In an old democracy like that of the United States, we have a mechanism to rectify the perceived lack of responsibility taken by elected officials, reminded Russell. Votes do matter.

Now is the time to trust our institutions and build a society that is committed to our future environment, health and quality of life—that’s the message Russel, Alley and many others conveyed.

Now is the time for individual action to promote collective reform. And it can start as early as November 3.

Shivani Majmudar is a health, environment and science reporter at Medill. You can follow her on Twitter at @spmajmudarr.

Melting glaciers on Mount Everest could threaten freshwater for millions and world economies

Melting glaciers on Mount Everest could threaten freshwater for millions and world economies

By Shivani Majmudar, Dec. 18, 2020 –

Amid this year’s global pandemic, the world is also fighting more frequent and severe hurricanes, larger wildfires and prolonged heat waves—indicative that climate change is real and it’s happening now.

“We’re at the blinking yellow light,” said Laura Mattas, a graduate research student at the University of Maine’s Climate Change Institute.

Mattas studies the Khumbu Glacier, located on the Nepalese side of the Himalayan mountain range. She’s working to identify and document its movement during the Last Glacial Maximum, the last period when ice sheets were at their greatest extent. The retreat of past glaciers provides scientists with the clues they need to predict the social and economic impact of human-driven accelerated climate change.

Her preliminary research, which she presented at this year’s virtual Comer Climate Conference, suggests this was between 18,000 and 23,000 years ago.

As warming temperatures and increased greenhouse-gas emissions melt glaciers, it also depletes the freshwater supply upon human and wildlife communities depend. (Shivani Majmudar/MEDILL)

Glaciers are strong measures of the total energy in a system because they respond to global temperature and precipitation fluctuations. In recent decades, glaciers have retreated significantly, as Earth’s rising average temperature melts ice more quickly than snow accumulates to replace it.

Beyond a marker for change, glaciers also provide a critical human and ecological resource: freshwater. As glaciers melt, not only are oceans desalinated to some degree, impacting the viability of marine life, but freshwater flowing into the oceans is lost in the salty mix. Water that millions of people rely on for household consumption, agriculture, and electricity is slowly draining.

The ripple effect of high glacial activity can even have far-reaching impacts on economic stability. For example, the eventual depletion of a primary source of water will cause a dramatic disruption of the supply chain that serves as the backbone of the economies of China, India, and the other countries that rely on water from the Hindu-Kush-Himalaya mountain range. Consumer prices would likely rise to counterbalance the expense of importing freshwater or desalinating seawater.

Melting mountain glaciers pose the same threats across the world. Closer to home, the mountains of California and Colorado are rapidly losing snow pack. Without action to slow climate change, serious environmental, health and economic consequences remain at stake.

Mattas is one of many environmental researchers studying the past to help inform our climate future at a time when the urgency for climate policy is assaulted by wavering acceptance of science. Veteran climate scientist Richard Alley, a professor at Pennsylvania State University and the master of ceremonies for the annual Comer Climate Conference, argues that climate history is the most reliable predictor of our future environment and the strongest asset to rebuild public trust in science.

“We need to keep people’s minds on the fact that we can solve these problems if we deal with them,” Alley said. “We’ve been successful in the past when we have used science and we have gotten along with each other.”

Mattas is particularly interested in the Khumbu Glacier because of its unique location. It is surrounded by both the cold atmospheric temperatures of the Himalayan mountain range and hot air masses from the warmest waters on Earth, the Indo-Pacific warm pool. This climate positions the mountain glacier well as an incubator of climate change around the world.

Freshwater from the glaciers of the Hindu-Kush-Himalayas feeds into the largest rivers across Asia, including the Ganges and Brahmaputra in India and the Yellow and Yangtze River in China. It directly supplies water to almost 2 million people.

Mattas’ research mapping the patterns and rates of glacial activity requires a combination of field work and data analysis. In April 2019, she and her team trekked the Khumbu Glacier in Dingboche, Nepal to collect samples of moraine—a landscape of rocks, gravel, and dirt that were once embedded in a glacier’s base but are gradually deposited at the glacier’s terminal edge, leaving a trail as it moves.

Glaciers retreat first in thickness before physically melting away. The team found that the modern Khumbu Glacier has approximately 600 meters less snow accumulation than during the Last Glacial Maximum, when the glaciers began to retreat about 18,000 years ago, evidencing how the glacier is shrinking as a result of the warming climate.

Moraines, signature hedges of rock cast off by the melting glaciers, also offer valuable insight into how long ago the rock emerged from the ice and has been exposed the air. The team measures the amount of Beryllium-10 in the sample, an isotope that forms in quartz when high-energy cosmic rays in the Earth’s atmosphere hit its surface. The concentration of 10Be offers a time machine for tracking how long the rock has been ice-free. Scientists call this clock cosmogenic nucleotide dating.

Additionally, they performed detailed photogrammetry, mapping that used the highest-resolution drones to have ever captured Mount Everest. Sampling and analyzing the rocks in the moraines surrounding the modern Khumbu Glacier allowed Mattas and her team to create a chronological, geomorphologic map of the periglacial and glacial landform activity in the Dingboche, Nepal, region.

The high-resolution drone Mattas and her team used was critical for their mapping and photogrammetry efforts. The image of the moraines at the Khumbu Glacier were the drones captured (right) were much more detailed than the most recent Google satellite image of the same area (left). (Laura Mattas/University of Maine)
A preliminary version of Mattas’ chronological, geomorphological figure, mapping the timing and extent of the Last Glacial Maximum for the Khumbu Glacier. From the inward to outward moraines, or most to least glacial movement, moraines formed around 18, 29, 36, 37, and 67,000 years ago. (Laura Mattas/University of Maine)

The preliminary 15 ages of moraines documented thus far suggests the timing of the Last Glacial Maximum for the Khumbu Glacier is consistent with similar research of glaciers around the world. Maps like the one Mattas has created are not only helpful for scientists to understand the rate and extent of glacial activity due to climate variability, but also serve as an important visual tool for the public and policymakers to recognize one impact of changing environmental conditions.

“[Maps] can tell us whether we need to prepare for giant floods and make flood walls or if this is a slow-moving process where we just raise the river banks,” Mattas said, The faster we can answer these questions, the better we can protect the communities who would be directly hit, she added.

Shivani Majmudar covers health, environment and science at Medill. You can follow her on Twitter at @spmajmudarr.


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