Archives_2020 – Climate Change

Scientists applaud President Biden’s White House science team and commitment to science

By Shivani Majmudar, Jan 22, 2021 –
President Joe Biden’s White House science team faces cascading crises as it takes command amid COVID-19, escalating climate change and crippling public doubts about science. But scientists across the country are confident the new administration is up to the challenge, especially under the leadership of science adviser Eric Lander, the pioneer who helped map the human genome.

Biden selected Lander, a renowned geneticist and mathematician, to be his science adviser and director of the White House Office of Science and Technology Policy (OSTP) before his inauguration. If confirmed, Lander will be the first life scientist to hold either position, as well as the first to hold Cabinet-level status.

“[Biden’s] appointment sends a powerful message that science will regain its place as the foundation for formulating the future of medical and health policy,” said Dr. Howard Koh, a physician and professor at Harvard University’s T.H. Chan School of Public Health, in an email.

Veteran geoscientist Richard Alley of Pennsylvania State University sees environmental issues and other science policy securing high priority as well. Not only is the recognition of biomedical sciences at the top positions in government long overdue, he said, but Lander’s expertise and knowledge of the scientific process also will inform policy solutions across all sectors.

President Barack Obama, left, confers with President’s Council of Advisors on Science and Technology Co-chairs Eric Lander, center, and Dr. John Holdren on March 27, 2015. (Official White House Photo by Pete Souza)

Lander was the principle investigator in the famous Human Genome Project, which sequenced the entire coding of human DNA in 2003. Under former President Barack Obama’s administration, he was co-chair of the President’s Council of Advisors on Science and Technology (PCAST) and advised the president on many issues that are still prevalent today including climate change, clean energy and vaccine rollout during the H1N1 influenza pandemic of 2009.

Lander will step down from his role as the founding director of the Broad Institute, a research collaborative of Harvard University and the Massachusetts Institute of Technology, to serve in the White House again.

“The science adviser is someone who brings science to the table of policy discussion and understands the difference between science and unsubstantiated opinion,” said science policy leader Andrew Rosenberg, who heads the Center of Science and Democracy at the Union of Concerned Scientists. “It’s what Lander can do and what I believe he will do.”

More broadly, scientists look forward to the dawn of a new era in which the nation’s leadership respects science, renews public trust in science and shapes evidence-based policy in the public’s best interest — a stark contrast from the past four years.

“It’s tough to have an influence if you’re not in the room,” Rosenberg said of scientists during former President Donald Trump’s administration. “There’s a lot of catching up to do.”

Biden has ambitious plans to do just that. To address the raging pandemic, he is committed to administering 100 million COVID-19 vaccines in his first 100 days in office. This comes as recent data from the Centers for Disease Control and Prevention suggests only 46% of all vaccine doses distributed so far have been administered.

Biden’s climate agenda is just as bold. It calls for the U.S. to achieve 100% clean energy and net-zero emissions by 2050.

Other priorities Biden set for the Cabinet-level science post include technological innovation, racial justice and long-term economic sustainability. Biden outlined these in a letter he wrote to Lander after his nomination.

Some scientists have reservations about the new team, particularly about the need to stress climate reform. Joellen Russell, a professor of biogeochemical dynamics and a leading national expert in climate science on faculty at the University of Arizona, said she is incredibly enthusiastic about the prospect of the country’s scientific future. But she added she is surprised the climate team was comprised mostly of lawyers and policy people.

“I think there are some gaps that are unlikely to be seen by people who are not climate scientists,” Russell said.

Russell is a strong proponent of accountability through public verification of federal action taken to mitigate climate change, such as policies to lower carbon emissions. Climate scientists are the best positioned to develop effective and accurate testing mechanisms, she said.

Russell agreed with Rosenberg and Alley, though, that the responsibility falls on the science community to support the administration and hold it to its commitments.

The rest of Biden’s science team is a diverse, deeply respected group of qualified scientists, including two prominent female co-chairs, bioengineer Frances Arnold and sociologist Alondra Nelson. If confirmed, Nelson will serve as OSTP deputy director for science and society, another White House first.

So far, Biden has followed through on many of the promises he was elected on. In his first two days as president, Biden signed at least 17 executive orders, including establishing a national mask and social distancing mandate on federal property, and rejoining the Paris climate agreement from which Trump withdrew the U.S. in 2017.

Rosenberg said he also hopes to see an executive order implementing a scientific integrity policy in all federal agencies — this would explicitly outlaw any political manipulation of science before it is presented to advisory boards or the public.

“There are a lot of big tasks ahead,” Rosenberg said. “But I’m sure Dr. Lander and the White House science team will be up to it.”

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

Even most scientists don’t know that this famous climate theory is flawed, researchers say

By Caroline Catherman, Dec. 30, 2020 –
New research has found a big flaw in one of the most widely accepted theories about earth’s climate, Milutin Milankovitch’s century-old theory of ice ages. This evidence, which echoes past findings, means that some long-term climate predictions could be more inaccurate than scientists realize, the researchers said. But they worry that this vital information won’t become general knowledge for years.

“It takes about a generation of new scientists to remove older ideas and bring newer ideas in,” said Thomas Lowell, professor of geology at the University of Cincinnati, during the recent Comer Climate Conference, an annual national conference held over Zoom this year.

Milankovitch proposed that cyclical changes in earth’s wobble, orbit shape and tilt relative to the sun cause ice ages. Figures are not to scale. (Animations and facts from nasa.climate.gov.)

The theory in question proposes that gradual changes in our planet’s movements and position add up over time to vary how much solar radiation reaches Earth. This variation in solar radiation affects whether each hemisphere experiences periods of cooler or warmer summers. Milankovitch predicted that thousands of years of colder summers cause ice ages.

“If you surveyed 100,000 geologists, 99,099 would say that’s correct, in terms of causing ice ages. But it has one big problem,” said Brenda Hall, a professor of glacial & quaternary studies at the University of Maine’s Climate Change Institute.

The theory’s hidden undoing

Milankovitch predicts that ice ages would occur at opposite times in the Northern and Southern Hemispheres. When one hemisphere was having cold summers, and heading towards an ice age, the other would be having warm summers, heading away from an ice age.

But Hall and Lowell’s new research from the Falkland Islands corroborates recent research in New Zealand by suggesting that the two hemispheres experienced the last major ice age, which peaked about 20,000 years ago, at nearly the same time.

These findings, currently undergoing peer review for publication, mean that scientists may not fully understand why the planet goes in and out of ice ages, said Hall.

This, Hall said, is crucial to understanding climate change.

“If we want to have any hope of making climate predictions, we need to know how the different pieces of the system work,” she said.

Hall added that researchers should begin considering other theories. One older theory is the idea that, rather than gradually shifting in and out of ice ages, earth’s climate rapidly changes due to sudden triggers. If true, this would have troubling implications for Earth’s future climate.

“If we can have ice age cycles, these massive changes in climate, because of very small changes … that tells us that a very small change could produce a big reaction. And we’re in the process of initiating one of those changes,” Hall said, referring to human-caused increases in greenhouse gas emissions.

But before many climate researchers will reconsider whether this theory is accurate, they must be convinced that the issue is up for debate.

Scientists are battling to replace a broken theory

Convincing scientists to consider alternative theories is a long process that some people have been attempting since as far back as 1984, when John Mercer published a paper with evidence of simultaneous ice ages.

“I feel like there have been some proposals as to, ‘what else could it be?’” said Meredith Kelly, associate professor of earth science at Dartmouth College. “Until we figure that out, and it’s really well tested, and well-explained, it’s not going to show up in textbooks.”

Lowell said that scientists in older generations are the biggest defenders of Milankovitch because they were taught to regard his theory as fact.

“If you look at the world, and everybody tells you it’s flat for 40 years … and you walk around and you discover that it’s not flat … you’re gonna have problems convincing people who haven’t traveled out of their flat sphere that the earth is round,” Lowell said.

Why Milankovitch’s theory gained acceptance

Several prominent studies have appeared to support Milankovitch’s theory. A 1976 study, for example, found evidence of a correlation between earth’s cycle in and out of ice ages and the so-called Milankovitch cycles. Lowell said these findings were strong enough that many people thought the issue was resolved, even though there was no evidence that this was a cause and effect relationship.

southern hemisphere research — Hall and Lowell’s research in the Falkland Islands took them to the top of Mount Osborne, where they used surface exposure dating to track ice ages by mapping the advance and retreat of glaciers over thousands of years. (Brenda Hall)

It also took a long time to build evidence against Milankovitch because the Southern Hemisphere wasn’t as well studied as the Northern Hemisphere. When scientists found evidence that the Southern Hemisphere came out of the ice age at the same time as the north, the evidence was initially dismissed as a fluke, said Lowell.

The new generation of scientists is key

“[The Milankovitch Theory] made sense. It wasn’t until you get into the details that you start pulling a thread, and it starts unraveling,” Lowell said. “It’s taken a long time… to get to where we are today.”

Lowell hopes that scientists in the next generation will weave up a new idea with the unraveled Milankovitch thread. For her part, Meredith Kelly has done her best to correct the canonical theory during her 12 years of teaching an intro to geology class, even as she gives her students a textbook that reveres Milankovitch.

“One of the students on the first day asked me if I was going to teach about Milankovitch, and I told her, ‘Yes, but I’m going to tell you that he’s wrong,’” Kelly said with a laugh.

Professors such as Kelly give Lowell hope.

“Science will march on,” he concluded.

Caroline Catherman covers health, environment, and science news at Medill. You can follow her on Twitter at @CECatherman.

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

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.

Next generation climate scientists study Earth’s responses to rapidly rising temperatures

By Grace Rodgers, Dec. 18, 2020 –

In a race against climate change, Yuxin Zhou, 26, is among the next generation of climate scientists studying the Earth’s responses to rapidly rising temperatures, threatening life on the planet.

As a fifth-year Ph.D. student at Columbia University’s Lamont-Doherty Earth Observatory, studying how the Earth’s climate behaved in the past is the best way for Zhou to understand the pace and consequences of climate change today.

In a similar way, to understand Zhou’s pathway into climate science, it’s important to look back on his journey to the present.

After graduating high school in Nanjing, China, Zhou moved to the United States to study computer science at the University of Southern California, Los Angeles. However, less than one year into the undergraduate program, he switched to geological sciences, inspired by his first earth science class.

“My deepest memory is my professor talking about his experience going into a submersible for research. He said it’s like looking down from an airplane onto New York City streets because it’s bustling with life,” Zhou said. “It was really that class that captured me and helped me become interested in earth science.”

Yuxin Zhou and Pablo Alasino working performing field work in Argentina. — While in Argentina as a University of Southern California undergraduate student, Zhou worked with professor Pablo Alasino (left) on geological mapping. (Yuxin Zhou//Columbia University)

While in undergrad, he also participated in multiple research opportunities in geochemistry, one of which was a summer fellowship at the Woods Hole Oceanographic Institution. He also gained publications in Nature Geoscience and Journal of Geophysical Research – Atmosphere.

From there, he moved cross-country to pursue a degree in earth and environmental sciences at Columbia University’s Lamont-Doherty Earth Observatory just outside of New York City.

“I just really wanted to continue to do the research, and earning a Ph.D. was the natural next step,” Zhou said.

As a current fifth-year Ph.D. student, Zhou’s research focuses on the factors destabilizing the circulation in the North Atlantic, spanning the past 150,000 years

Jerry McManus, a geochemistry professor and researcher at Lamont-Doherty, works closely with Zhou as his research advisor and has seen his growth as a young scientist in the field.

“He started his Ph.D. working on more recent climate issues, and then became interested in paleoclimate and in geochemistry. He’s gone up a learning curve and has done brilliantly,” said McManus. “I work with wonderful, bright junior people, and if I can stay out of their way and help them to do their great work, then that works out the best all-around.”

Yuxin Zhou standing at a podium presenting his research at the Goldschmidt geochemistry conference in Barcelona. — While at the Goldschmidt geochemistry conference in Barcelona, Zhou presented his research on the history of iceberg discharge in the western North Atlantic. (Athena Nghiem//Columbia University)

In early October, both Zhou and McManus presented their new research at the Comer Climate Conference, an annual summit where climate scientists from around the world gather to present emerging research.

Zhou’s presentation focused on his new method to track and measure the amount of freshwater released by melting icebergs following Heinrich events. Icebergs break off from glaciers into the ocean all the time, but Heinrich events are special in that a large number of icebergs do so in a short amount of time. These events can impact ocean circulation and in turn, weather temperatures, storms and rainfall across the globe.

Unlike existing research on iceberg melting in the North Atlantic, Zhou’s new method measures the amount of freshwater and the location of freshwater released. Much of his research is based on new and previously published measurements of sediment cores collected from ocean floors in the North Atlantic.

In measuring these sediment cores, Zhou can identify specific elements and isotopes within sections of the core that correlate to the amount of freshwater released by melting icebergs during a certain period of time. The correlations follow past ice ages and warm spells, which can help predict the pace of climate change today.

“I have the opportunity to use and apply cutting edge technologies to analyze the cores,” Zhou said. “It’s very inspiring to me because you’re not thinking about your own or your own generation’s scientific career, but 10s of years in the future.”

While at Lamont-Doherty, Zhou has worked alongside Celeste Pallone, a 2nd-year Ph.D. student.

“The biggest things I’ve learned from his work is both how he does lab work, but also how he organizes and prepares his data,” said Pallone. “I’ve learned what kind of statistical methods he uses to back up his claims, and just how to do good science.”

Yuxin Zhou standing at a booth with Jennifer Middleton presenting their research at the annual Lamont-Doherty Earth Observatory open house. — During the annual Lamont-Doherty Earth Observatory open house, Zhou worked with a team (right: Jennifer Middleton, a postdoc researcher) on an exhibition about iron availability in the ocean. (Yuxin Zhou//Columbia University)

In addition to earning his Ph.D., Zhou hopes to remain in academia, working with students in science. For the past two years, Zhou has volunteered for the nonprofit Girls Who Code, teaching high school girls how to create a website. He has also worked as the Graduate Student Committee chair at Lamont-Doherty Earth Observatory, advocating for student concerns to the department and pushing for student representation on hiring committees.

“Having an inclusive teaching environment and active learning experience is very important to me,” Zhou said. “We want to make sure that hiring has a certain voice on it, and hopefully, that will translate to more diversity, equity, and inclusion.”

Looking into the future, Zhou hopes to work with other climate scientists to help predict and mitigate the effects of climate change. Having comparisons between data observations and model simulations can be a very powerful tool to narrow down estimates on the freshwater fluxes and their impacts, Zhou said.

“What we’re seeing now is unprecedented. We do have some imperfect analogs of the current scenario in the past,” Zhou said. “But by better understanding those past events, we establish a baseline of what may happen in the future.”

For a deeper dive into Zhou’s research process, read “Breaking down clues to climate change from ocean floors to measure iceberg melting“on Medill Reports.

Grace Rodgers is health, environment and science reporters at Medill. You can follow her on Twitter at @gracelizrodgers.

Rare-earth metal reveals ancient ocean currents linked to climate triggers

By Marisa Sloan, Dec. 18, 2020 –

Despite the sci-fi name of this rare-earth element, neodymium is actually pretty common. The silvery metal is used in everything from cell phones and wind turbines to tanning booths and electric guitars.

But it’s the neodymium found thousands of meters below the ocean’s surface that captured the interest of Dr. Sophie Hines, a postdoctoral research fellow at Columbia University’s Lamont-Doherty Earth Observatory.

Hines traced the metal trapped within ancient marine sediments to reconstruct changes in ocean circulation reaching as far back as one million years ago. She presented her research at the Comer Climate Conference, an annual meeting of climate scientists that was held virtually this October.

“The ocean neodymium cycle is something that people have been studying for a long time,” she said. “But there are still parts that we’re learning.”

Because the global ocean circulation system brings water from the surface down to the deep ocean, it is thought to play an important role in trapping atmospheric carbon dioxide and triggering global climate changes.

According to Hines, different forms of neodymium wind up in the ocean through the weathering of various rocks and minerals. The neodymium composition of the North Atlantic Ocean, which is characterized by older continental crust, is distinct from that of the Pacific Ocean, which has more volcanoes and newly erupted material. These differences make it easier for climate scientists to trace the movement of seawater away from its sources and reconstruct changes in deep ocean currents.

“Trying to figure out how the ocean impacted climate in the past is interesting in and of itself,” Hines said. “But it also serves as an important calibration data set to make sure that the models we’re using to look at future climate change are accurate.”

Right now, the oceans provide a huge “carbon sink,” absorbing much of the carbon dioxide emissions from fossil fuels that are warming the planet at a threatening pace. The less carbon dioxide there is in the atmosphere, the colder the planet becomes.

According to a 2019 report by the Intergovernmental Panel on Climate Change, smaller glaciers will melt by more than 80% by the end of the century if greenhouse gas emissions continue on their current trajectory. The resulting influx of fresh water will likely disrupt ocean currents and, by extension, the climate in a way humans have yet to see.

Even if emissions were stabilized tomorrow, it would take many years for the oceans to adjust to the 1° C rise in global temperatures that has already occurred.

In 2016, Hines joined a two month-long deep-sea drilling expedition to South Africa’s Cape Basin on a whim when another researcher couldn’t make the trip. Although she was wrapping up the final year of her PhD program, she had yet to work in the field and didn’t know what to expect.

Location map of Integrated Ocean Drilling Program Site U1479, approximately 85 nautical miles southwest of Cape Town, South Africa. Water in this region comes from a complex mix of sources, including the North Atlantic, Indian and Southern Oceans. (Marisa Sloan/MEDILL)

“I was on the day shift, which [was] from noon until midnight,” Hines said. “Every day we did all this science, and then in the time we had off we hung out and watched movies and watched the stars at night.”

The first few weeks were new and exciting, she said. Each scientist onboard had his or her own tasks to do, ranging from dating the 9-meter-long sediment cores by their micro-fossils to squeezing water out of them with a hydraulic press.

By the time the sixth week rolled around, however, everyone was stepping on each other’s toes.

“Then we made it to Cape Town and had a big party,” she said, laughing. “I remember being most excited to have a beer and eat a salad by the end.”

The Cape Basin, where Hines traveled in search of ancient sediment cores, lies in The South Atlantic Ocean between the North Atlantic and the Pacific. Her chemical analysis shows a shift toward more Pacific-like water in the area during the last glacial period, from approximately 110,000 to 12,000 years ago⁠, perhaps revealing an ocean circulation that sequestered carbon dioxide-rich water in the Pacific and stored it in the South Atlantic.

Bob Anderson, a founder of the international program GEOTRACES and professor at Columbia’s Lamont-Doherty Earth Observatory, said her results correlate well with similar studies on carbon and carbonate ions.

“I agree [with Hines], but I don’t think we can make that as a final conclusion yet,” he said. “We know from a lot of neodymium data coming out right now that it’s more complicated than people used to think.”

In fact, another study published earlier this year posits an opposite conclusion. It suggests the changes in neodymium concentration in the South Atlantic may actually be a result of changes in the North Atlantic, rather than a switch to water from the Pacific.

“What I think we need are more records from the shallow to mid-depth North Atlantic and from the Pacific,” Hines said.

That’s the goal of Anderson’s program GEOTRACES, which is designed to study traces of neodymium and a barrage of other elements found within all of the earth’s major ocean basins. So far, scientists from approximately 35 nations have been involved in the expeditions to better understand how the chemical environment affects ecosystem function and vice versa.

Anderson said he expects those mysteries will be better understood in the next few decades, although he will likely be cheering on scientists like Hines from the sidelines by then.

“It will take combining the data that I collected with other people’s data to try and get a more holistic understanding of what happened,” Hines said. “That’s the hard part. And it’s also the fun part.”

Marisa Sloan is a health, environment and science reporter at Medill. You can follow her on Twitter at @sloan_marisa.

BREAKING DOWN CLIMATE CLUES FROM OCEAN FLOORS TO MEASURE ICEBERG MELTING

By Grace Rodgers, Dec. 18, 2020 –

Melting freshwater icebergs raise critical questions about ocean circulation. However, to find answers to what’s happening on ocean surfaces, some scientists are searching ocean floors for evidence of past environments and clues to the pace of current climate change.

As a fifth-year Ph.D. student at Columbia University’s Lamont-Doherty Earth Observatory, Yuxin Zhou’s research focuses on the factors destabilizing the circulation in the North Atlantic, spanning the past 150,000 years. The majority of his findings are based on new and previously published measurements of long tubes of sediment cores collected from ocean floors in the North Atlantic.

“Model simulations can be a very powerful tool to narrow down the spread off of estimates we have on the freshwater fluxes,” Zhou said.

Prior to the pandemic, he spent long weekdays working at Lamont-Doherty in the Palisades near New York City. However, due to stay-at-home orders, he has been on campus for only three to four weeks in total since March.

When Zhou does travel to the campus, entering the laboratory requires an extensive sanitation protocol. He must change into the appropriate lab attire, which includes long pants, long sleeves, closed-toed shoes, gloves, goggles, a mask, and a lab coat. After stepping onto a sticky mat to remove dust particles from his shoes, Zhou can enter the lab and begin working.

Measuring 18 data points from one sediment core can take up to two weeks but provides key data on specific elements and isotopes within the sediment, and indicates the amount of freshwater released by melting icebergs during a certain period of time.

To begin the measuring process, Zhou begins by removing a small portion of the sediment core and places the solid sediment into a heat-and acid-resistant container. He then uses heat and several types of acids, including hydrofluoric acid, to gradually dissolve the solid sediment into a liquid solution.

Yuxin Zhou working on scientific processes at the Lamont-Doherty Earth Observatory laboratory. — While working in the Lamont-Doherty Earth Observatory laboratory, Zhou wears full personal protective equipment including a lab coat, face mask, goggles, and gloves. In the lab, Zhou works on various scientific processes including column chemistry (right). (Yuxin Zhou // Columbia University)

Once a dissolved liquid, it’s time to begin a chemical process called column chemistry, which filters and separates elements in the liquid. The chemical process results in a concentrated liquid containing three primary elements, which Zhou needs to measure the iceberg meltwater: thorium, protactinium, and uranium.

Finally, the concentrated liquid is placed into a machine to test the concentration of each isotope. With conclusive measurements, Zhou can determine the amount and location of freshwater released by icebergs in the North Atlantic.

The remainder of the sediment core is archived in the Lamont-Doherty’s core repository, one of the largest such repositories in the world. With accessibility to decades of core sediments collected from around the world, Zhou hopes his new method will contribute to scientist’s global efforts to predict and mitigate the effects of climate change.

“The best minds in the world have been working on this for a very long time,” Zhou said. “The scientists have nothing other than the best interest of science and the human society when they devote their careers to these questions about climate change.”

For the full story on Zhou and his journey to the present, read “Next generation climate scientists prepare for the future by studying past North Atlantic iceberg melting” on Medill Reports.

Grace Rodgers is health, environment and science reporters at Medill. You can follow her on Twitter at @gracelizrodgers.

New glacial chronology lays groundwork for understanding rapid melt of modern ice sheets with climate change

By Grace Rodgers, Dec. 18, 2020 –

Researchers have long tracked the timing and retreat patterns of the North American Laurentide ice sheet, the greatest ice sheet to exist in the Ice Age. During that time, nearly two-thirds of the rise in the global sea level was caused by the melting of the Laurentide — the majority of which occurred over 10,000 years.

“That’s an interesting, dynamic problem. In many senses, they’re very few other elements that size on the planet that change that rapidly,” said Thomas Lowell, a geology professor at the University of Cincinnati.

For over 40 years, Lowell has studied the Laurentide and tracked two key behaviors the ice sheet exhibited during climate changes: the amount of meltwater and ice margin retreat. Lowell presented his most recent research on these two behaviors at the annual Comer Climate Conference, an annual summit where climate scientists from around the world gather to present emerging research.

Over a five-year research process, Lowell and a team of scientists assembled the first-ever annual chronology tracking the amount of meltwater released and the rate at which the Laurentide retreated. The chronology begins nearly 12,700 years ago and spans a 1,500-year transition between the late Younger Dryas, a geologic interval of colder temperatures, and the Holocene boundary, a geologic interval of warmer temperatures.

Lowell predicted the measurements would show a slower retreat rate and less meltwater during the cold interval, and a faster retreat rate and more meltwater during the warm interval. However, the chronology revealed the meltwater doubled at the transition between the cold and warm interval, while the ice sheet retreated at a constant rate.

“If you melt a glacier more, you expect it to shrink faster. But the interval that we recorded, [the retreat rate] didn’t seem to be paying attention [to the temperature],” said Lowell. “Even though it was melting faster, it was still backing up and retreating at the same rate.”

While melting in warmer temperatures was expected, Lowell was surprised the glacier retreated at the same rate despite the higher meltwater.

“There’s nothing super exciting about the [meltwater] findings, but coupled with the [retreat rate] findings, they seemingly conflict with each other,” said Lowell.

The team of scientists working on the frozen ice using measuring equipment. — The team of scientists spent roughly four weeks researching and plotting core sites for the varve chronology. Afterward, the team spent roughly six weeks collecting the sediment cores across frozen lakes in Central North America. (Dr. Andy Breckenridge//University of Wisconsin)

To quantify the amount of glacial meltwater, Lowell and the team of scientists recovered roughly 1,000 meters total of sediment cores, one meter at a time across lakes in Central North America. Back in the lab, scientists measure the core’s “varves”, the thickness of sediment layers deposited in one year. Each varve indicates the amount of melting that occurred in one year: the thicker the layer, the more meltwater.

Altogether, the sediment cores serve as a chronology of meltwater. Measuring varve units can be critical for assessing the response of both past and present ice sheets to climate change.

“[Varves] were an archive that we really needed to understand the ice,” said Dr. Andy Breckenridge, lead author and a geology professor at the University of Wisconsin. “We knew the record was there and we designed a strategy where we were going after modern lakes to reconstruct it.”

The Geographic Information System equipment taking a photo of a sediment core. — Using a Geographic Information System at the University of Minnesota, Breckenridge captures a high-resolution image of the sediment cores to measure each varve. (Dr. Andy Breckenridge//University of Wisconsin)

Breckenridge measured each sediment core, beginning by taking high-resolution scans to survey the varve thickness and color. Lighter layers indicate summer seasons, meaning the sediment is coarser due to warmer temperatures. Darker layers indicate winter seasons, meaning the sediment finer grain due to colder temperatures. Once tallied on a spreadsheet, Breckenridge identifies thickness patterns to organize the varve chronology.

While one half of the cores are used for data collection, the other half is stored in a refrigerated warehouse allowing researchers from around the world to come and study the chronological cores.

“[Other researchers] are going to be able to request samples from our cores,” Breckenridge said. “And that’s already happened at some of our sites. I know some of our cores have been used for a carbon storage question”

Now that these findings are published, Lowell’s current research question asks: are these melting patterns a behavior of the whole ice sheet or just a small part of it, and if so, is that small part important. Further research into past and present glacial melting is critical to help us understand sea level change that threatens the livelihood of millions around the world.

“The ice sheets have the potential to change sea level, enough to really matter to society,” said Lowell.

Grace Rodgers is health, environment and science reporters at Medill. You can follow her on Twitter at @gracelizrodgers.

56-million-year-old algae could shed light on future climate change

By Marisa Sloan, Dec. 17, 2020 –

Faced with a challenge as mammoth as climate change, scientists are turning to some very tiny organisms for insight — coccolithophores, the single-celled algae that are smaller than a grain of sand.

In order to grow, algae use sunlight to convert carbon dioxide and water into energy in a process called photosynthesis that all plants employ. The algae prefer to take up the lightest of two different forms of carbon, but sometimes resort to the heavier form when carbon dioxide levels in the surrounding water are low.

Louis Claxton, a Ph.D. student at the University of Oxford, uses the ratio of light to heavy carbon trapped in the algae’s fossilized shell to approximate the amount of carbon dioxide in the ocean when it lived. He presented his research at the Comer Climate Conference, an annual conference of global climate scientists that was held virtually this October.

“These things are gorgeous to look at under the microscope,” Claxton said. “And something so small, something that no one really pays much attention to, can hold so much information about our past.”

Right now he examines algae from a period in Earth’s history called the Eocene, which lasted from approximately 34 to 56 million years ago. It was a time marked by hot temperatures, rapid changes in climate and a lack of permanent ice sheets. This was the last such extreme heat spell Earth experienced and scientists believe the period could hold important implications for where today’s warming climate is heading.

“If we can understand how biology responded to changes in carbon dioxide over this period, we may be in a better place to understand how it may change in the future,” Claxton said.

And it is changing.

According to the Intergovernmental Panel on Climate Change, the current amount of atmospheric carbon dioxide exceeds measurements from at least the past 800,000 years. That increase, at a rate unprecedented in modern history, has largely been caused by the burning of fossil fuels and led to surging global temperatures, rising sea levels and severe weather patterns.

“In dealing with these big issues, the history of climate is absolutely essential,” Dr. Richard Alley, a geoscientist at Pennsylvania State University, said during the conference. “History gives us a way to test models.”

By growing algae in his lab and subjecting them to various levels of carbon dioxide, Claxton can create models that predict how ancient algae reacted to similar changes in carbon dioxide levels.

“They are nightmare pets because they are very sensitive to temperature and all sorts of things,” he said. “But I’ve been looking after them for about three or four years, and I’ve gotten quite attached to them.”

Sophie Gill, another Ph.D. student within Claxton’s research group, knows all about that.

“I work on slightly different species because some of the species I work on weren’t evolved during the time that he works on,” she said. “But we’re able to see a common ground [in that] some coccolithophores are not able to cope with very high levels of dissolved [carbon dioxide].”

Gill is currently trying to find the perfect oceanic conditions that will allow the algae to take up more carbon dioxide through photosynthesis than they produce via their calcium carbonate shells. She hopes the algae may someday be used as a more effective carbon sink, absorbing large amounts of carbon dioxide from the ocean’s surface and trapping it within their fossils when they die.

The concept seems ideal on the surface, but Claxton is digging into the past — literally — for any unintended consequences it could have.

“The samples come from about 1,500 meters deep off the coast of Namibia,” he said. “If you were to hold some of the sediment that I was working with in your hand, it looks like… slimy mud that someone’s dug up from the bottom of a puddle.”

Hidden within that mud, however, are the fossilized remains of algae that lived tens of millions of years ago. When Claxton compares their carbon composition to his models, he is able to estimate the carbon dioxide levels in the ocean, and by extent the atmosphere, at the time the algae lived.

So far, his calculations correspond well with existing data from various other methods. Now that Claxton has proven the concept works, he’s ready to jump into the unknown: time periods in the even farther past for which there are no well-constrained data.

“The method that I’m working on to reconstruct carbon dioxide could potentially go back about 200 million years,” he said, referring to how long ago this particular type of algae evolved.

In comparison, ice core records extend to only about 800,000 years.

“We may be missing analogs in Earth’s history that are almost identical to today,” Claxton said. “By identifying those periods, we can perhaps understand what the future may hold.”

Marisa Sloan is a health, environment and science reporter at Medill. You can follow her on Twitter at @sloan_marisa.

Trump warns the Green New Deal will ‘take out the cows.’ Here’s the science showing why that’s a myth.

By Carlyn Kranking and Grace Rodgers, Nov. 19, 2020 –

At the first 2020 Presidential debate, President Donald Trump said that Green New Deal supporters “want to take out the cows” to reduce greenhouse gas emissions.

Not only is this claim untrue, but eliminating cows, which notoriously produce the greenhouse gas methane, isn’t necessary to address climate change, according to University of Oxford researchers.

“It would be good if you maybe ate less beef, had less milk — but we don’t need to completely get rid of all the cows,” said John Lynch, postdoctoral researcher at the University of Oxford.

Lynch studies ways to anticipate the impacts of greenhouse gases and suggests that the greenhouse gas carbon dioxide is more important to address than methane. It takes much less time to reverse the impact of methane emissions than it does to undo the effects of carbon dioxide, so it’s possible to delay addressing methane, he said. His suggestion has huge implications, because the way greenhouse gases are reported and compared in policies today doesn’t make it clear how differently these gases behave.

The Global Warming Potential (GWP) is a metric used to compare how much different greenhouse gases will warm the atmosphere across a given period into the future. Organizations including the U.S. Environmental Protection Agency and U.N. Intergovernmental Panel on Climate Change publish the GWP in their reports.

However, Lynch’s research shows that, for some purposes, the GWP metric may be misleading. Reporting all gases as though they were on the same playing field, experts say, does not account for key differences between them, especially between methane and carbon dioxide.

“Metrics that try and treat the gases in the same way are always going to have limitations,” Lynch said.

A figure from Lynch’s report demonstrates the differing effects of carbon dioxide and methane on warming over time.

In the first few decades after it’s emitted, methane causes more warming per kilogram than carbon dioxide does. Methane, however, breaks down after about 12 years, while carbon dioxide accumulates in the atmosphere, warming the planet for millennia.

Calculating warming potential over 100 years, for instance, does not account for how strongly methane warms the planet initially, nor does it account for the full effects that CO2 emissions will have.

So, if the GWP measurement is misleading, what does this mean for potential policies based on that statistic?

It would be best to cut both carbon dioxide and methane emissions, Lynch said. But because governments have limited will and resources to address the problem, he said it is more important to achieve net zero carbon emissions before cutting methane.

“If we prioritize the methane, first we will have a large quick benefit” as methane levels in the atmosphere rapidly fall, Lynch said. “But in the meantime, we will have carried on emitting all the CO2 that we decided not to bother with because methane looks easy. And then, in a couple of decades, we’ll be stuck with that CO2 warming, whereas if we just delayed our action on methane, we’d still be able to reverse that.”

Still, governments should not ignore methane emissions in climate policy, as all greenhouse gases warm the planet, Lynch said. But ultimately, the most important thing to do is to get to net zero carbon dioxide, because that’s the gas with the longest-lasting and biggest impact on global warming.

“There’s a lot of harm in delaying things that address carbon emissions,” said physicist Raymond Pierrehumbert, a professor and statutory chair in the physics department at the University of Oxford.

These long-lasting emissions will warm the planet, causing more extreme weather conditions, droughts, floods and rising sea levels. The longer it takes to reach net-zero CO2 emissions, the more severe these effects will be.

That’s why Lynch feels we “don’t really have a choice” on whether or not to decrease carbon emissions.

“All of your energy needs to be decarbonized,” Lynch said. “If we don’t, we’ll never stop the temperature going up.”

Carlyn Kranking and Grace Rodgers are Health, Environment and Science reporters at Medill. You can follow them on Twitter at @carlyn_kranking and @gracelizrodgers.

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