A phenomenon that typically occurs every two to seven years, El Niño causes much warmer than average ocean temperatures in the eastern Pacific, significantly affecting weather around the globe.  

The Quelccaya Ice Cap (QIC) in the Peruvian Andes has been shown to be sensitive to these climate shifts, but the extent to which El Niño contributes to its continued shrinkage has, to date, been unclear. 

Now, using images captured by NASA Landsat satellites over the past four decades, researchers have confirmed that the regional warming periodically caused by El Niño has indeed resulted in a drastic reduction of its snow-covered area. The study, led by Kara Lamantia, a graduate student at the Byrd Polar and Research Climate Center at The Ohio State University, found that between 1985 and 2022, the QIC lost about 58% of its snow cover and about 37% of its total area. 

“Our research gives us a look into a glacier’s health,” said Lamantia. “The Quelccaya glacier becomes greatly out of equilibrium during these short-term climate anomalies.”

The study, published today (October 8, 2024) in the journal The Cryosphere, is the first to automate the process of snow-covered area detection on the QIC. Normally, this detection is only possible through extensive field measurements or manually hand-tracing satellite images that are clear enough to detail the visual boundary between snow and ice. 

Yet an algorithm this team developed processes images using near-infrared imagery, a method that utilizes wavelengths outside our visible spectrum. “By creating a threshold for the different reflectance between snow and ice cover, we can gather a consistent and much more reliable measurement,” said Lamantia. 

Glaciers and ice caps gain mass by accumulating ice and snow and lose it when none is received, or more ice is lost than gained. By measuring the ratio of snow-covered area to the total area, researchers can quantify whether the QIC is gaining mass, losing it, or maintaining a steady state. 

The study revealed that during El Niños, the ratio drops significantly away from the average, indicating a drastic reduction in the snow-covered area. 

This extreme change in its ratio may be attributed to the wide differences between the dry and wet seasons in southern Peru, said Lamantia.

“All of the snowfall happens during the wet season, but during an El Niño, southern Peru experiences warmer and drier conditions than average so it stays dry throughout the wet season,” she said. “That means that the snow cover will continue to decline and there might be quite a bit less snowfall to replace it.”

As climate change rapidly alters the Earth’s environment, it’s expected that El Niños are likely to be longer-lived and stronger, a factor that will accelerate ice loss. This raises the possibility of the QIC’s snow cover failing to recover during La Niñas, or periods when the oceans should be cool.

“The ice cap as a whole is on a very consistent linear decline from anthropogenic warming,” said Lamantia. “It may not matter how strong future La Niñas are, as the freezing line continues to rise and snow cover shrinks, Quelccaya will likely continue to decline.”

If this carries on, some projections suggest that snow cover on the QIC could disappear by 2080, relegating it to a wasting ice field, much like Kilimanjaro. By the end of the century, the study notes, the ice cap could be no more.

It’s difficult to discern how other short-term weather events might impact glacier vulnerability, which is something similar studies may aim to model in the future. What scientists do know is that ice loss puts high-mountain communities that depend on them in jeopardy, as snow loss can quickly diminish key water supplies. 

The damage already done to the oceans and atmosphere is not something we can reverse tomorrow, Lamantia said. Using the data collected about their complex interactions, researchers may have a better chance at monitoring and mitigating the planet’s climate woes.

“The general consensus is we can expect that the likely increased intensity and duration of El Niños will cause more complications for the QIC,” said Lamantia. “We need to start being clever about how we use and conserve our water resources.”

This study was supported by the National Science Foundation, the Heising-Simons Foundation and the Volo Foundation. Other co-authors were Lonnie Thompson and Bryan Mark from Ohio State and Laura J. Larocca of Arizona State University. 

For decades, the Guliya Glacier, located above 20,000 feet in the far northwestern Tibetan Plateau, has been one of the richest archives available to scientists to investigate large-scale paleoclimate shifts. Now, by analyzing recovered ice core samples from the glacier, microbiologists have reconstructed pieces of virus DNA that were left within them and identified nearly 1,700 viral species, of which about three-fourths are newly discovered. 

Drilling into prehistoric ice doesn’t have health implications for modern humans, because these long-dormant viruses likely infected other dominant microbes rather than animals or humans, but researchers found that their adaptations significantly influenced their hosts’ ability to survive in extreme conditions during variations in Earth’s climate cycles.

“Before this work, how viruses linked to large-scale changes in Earth’s climate had remained largely uninvestigated,“ said ZhiPing Zhong, lead author of the study and a research associate at the Byrd Polar and Climate Research Center at The Ohio State University. “Glacial ice is so precious, and we often don’t have the large amounts of material required for virus and microbe research.”

As unprecedented warming continues to hasten glacier melt, the race to collect these ice cores before they disappear for good has only served to increase their scientific value. For instance, the layers of ice researchers examined in this paper provided pristine snapshots of how viruses behaved during three cold-to-warm periods over the last 41,000 years.

The study was published today in Nature Geoscience. 

Of the various types of new viruses reported, the most distinct viral community the team observed dates to about 11,500 years ago, a time during which a major climate transition from the cold Last Glacial Stage to the warm Holocene occurred. 

This suggests that microorganisms were reacting to climate changes as global temperatures shifted from cool to warm, but it is still too early to say for certain, said Zhong. “This at least indicates the potential connection between viruses and climate change,” he said.  

Using advanced sequencing technologies to get a closer look at their genetic signatures, the team’s results also showed that although most of the viruses found in the glacier were unique to Guliya, about one-fourth overlapped with known organisms from other areas of the world. “That means some of them were potentially transported from areas like the Middle East or even the Arctic,” said Zhong.  

Taking the time to better understand how viruses evolved during intense climatic eras offers vital insights into predicting how modern viruses are likely to react to and engage with future ecosystem warming, researchers say. Moreover, because organisms found in ice cores expand the diversity of information researchers can learn about those periods, finding and sequencing new swaths of ancient viral DNA could lead to an explosion of both new mysteries and new conclusions. 

“To me, this science is a new tool that can answer basic climate questions that we couldn’t have answered otherwise,” said Lonnie Thompson, co-author of the study and a professor in earth sciences at Ohio State.

Sharpening these techniques on Earth will likely provide scientists with fresh tools to broaden the search for life in outer space environments, aiding efforts to find microbes in the ice fields on Mars or underneath the icy shells of other planetary bodies, said Thompson. 

Investigators looking to make further viral and climate connections here on Earth could also benefit from upcoming advances in technology as well as diverse scientific approaches to research, the study notes. Yet, the authors asserted, the clock is ticking: These techniques must be implemented before warming compromises the glacial ice needed to preserve and further explore Earth’s rich history. 

“I'm optimistic about what can be done here, because if we work together, these techniques have much potential to help us start tackling a large array of scientific issues,” said Thompson. 

Matthew Sullivan, co-author of the study and a professor of microbiology and civil, environmental and geodetic engineering at Ohio State, said the study’s success can be attributed to how well the interdisciplinary approach taken by Ohio State’s Byrd Polar and Climate Research Center and the Center of Microbiome Science has helped incubate new science.

“This kind of opportunity represents several disciplines coming together, each with their own scientific languages as a barrier to proceed,” he said. “But getting to study ancient viruses and microbes in ice with this team is a testament to the support we had to explore new interfaces.”

The study was supported by the National Science Foundation, the Chinese Academy of Sciences, the Gordon and Betty Moore Foundation, the Heising-Simons Foundation and the U.S. Department of Energy’s Joint Genome Institute and their Community Sequencing Program. 

Other co-authors include Ellen Mosley-Thompson, Olivier Zablocki, Yueh-Fen Li and Virginia Rich of Ohio State, as well as James Van Etten of the University of Nebraska. 

Despite feeling like a stationary mass, most solid ground is undergoing a process of deformation, sinking and rising in response to many environmental factors. In Antarctica, melting glacial ice means less weight on the bedrock below, allowing it to rise. How the rising earth interacts with the overlying ice sheet to affect sea level rise is not well-studied, said Terry Wilson, co-author of the study and a senior research scientist at the Byrd Polar and Climate Research Center at The Ohio State University. 

In the new study, Wilson’s colleagues at McGill University developed a model to predict how these interactions could impact global sea level, finding that if humans can lower greenhouse gas emissions and global warming is slowed, upward shifts in the solid earth could reduce Antarctica’s contribution to sea level rise by about 40%, significantly bolstering the best case scenarios for global sea level rise. In this low-emissions scenario, land uplift slows the flow of ice from land to ocean, allowing for more of the ice sheet to be preserved. 

Conversely, if humans are unable to lower carbon emissions in time, ice retreat will outpace uplift, pushing ocean water away from Antarctica and amplifying sea level rise. These events could significantly worsen the most dire models of projected sea level rise along populated coastlines, said Wilson. 

“Our measurements show that the solid earth that forms the base of the Antarctic ice sheet is changing shape surprisingly quickly,“ said Wilson. “The land uplift from reduced ice on the surface is happening in decades, rather than over thousands of years.” 

The study was published today in Science Advances. 

To arrive at these conclusions, the team developed a 3D model of the Earth’s interior using geophysical field measurements from the Antarctic Network (ANET) of the Polar Earth Observing Network (POLENET) project. The mission is focused on studying the changing polar regions by collecting GPS and seismic data from an array of autonomous systems across Antarctica.

Researchers then performed a number of simulations to capture many possible evolutions of Antarctica’s ice sheet and the extent of global sea level rise Earth may experience until the year 2500, according to those parameters.  

 “We can project what difference it actually will make if we all contribute to a low-emission scenario now, versus what’s come to be called ‘business as usual’ emissions,” said Wilson, who is also the lead investigator of the ANET-POLENET project. 

She attributes the model’s unprecedented level of detail to how deftly it incorporates data from Antarctica. GPS stations monitor how the land is moving and seismometers measure how fast seismic waves from earthquakes travel through the earth, yielding important insight into where the land uplift will be fast or slow. 

Surprisingly, according to some of the team’s GPS observations processed by researchers at Ohio State, Wilson said, the Antarctic Ice Sheet is currently experiencing a solid earth uplift of about 5 centimeters per year, about 5 times the rate that North America experiences.  

Another significant aspect of the study is how the changes in Antarctica under different carbon emissions scenarios will impact coastlines around the world. Because sea level change will not be uniform, the study notes that nearly 700 million people around the world living in coastal regions will be most impacted by rising seas due to Antarctic ice loss.

Since some regions, such as small island nations, will be more vulnerable than others, mitigating environmental conditions like atmospheric and ocean warming is a vital issue for society, said Wilson. 

“Many people are now more aware they’re experiencing the effects of climate change,” she said. “This work reinforces that our actions as individuals, nations and globally can make a difference in what kind of Earth our offspring will experience in their lifetimes.”

The study results highlight how complex the relationship between the solid earth and the processes that happen atop it is, as well as the importance of continuing to gather enough data to make prompt and accurate predictions about what the next few centuries of our planet will look like. 

“There’s a lot of uncertainty in every model and every prediction that you make,” said Wilson. “But to document how fast our world is changing, it’s very important to continue advancing our ability to make predictions that are more certain, which is the only path that will allow us to tend to our future in a meaningful way.”

Wilson completed the study with colleagues from McGill University, Pennsylvania State University, the University of Massachusetts Amherst, Columbia University, Washington University, Colorado State University and the Union of Concerned Scientists. This study was supported by the U.S National Science Foundation and the Natural Sciences and Engineering Research Council of Canada.