Atmospheric Sciences

Geosciences Column: Using volcanoes to study carbon emissions’ long-term environmental effect

Geosciences Column: Using volcanoes to study carbon emissions’ long-term environmental effect

In a world where carbon dioxide levels are rapidly rising, how do you study the long-term effect of carbon emissions?

To answer this question, some scientists have turned to Mammoth Mountain, a volcano in California that’s been releasing carbon dioxide for years. Recently, a team of researchers found that this volcanic ecosystem could give clues to how plants respond to elevated levels of carbon dioxide over long periods of time. The scientists suggest that studying carbon-emitting volcanoes could give us a deeper understanding on how climate change will influence terrestrial ecosystems through the decades. The results of their study were published last month in EGU’s open access journal Biogeosciences.

Carbon emissions reached a record high in 2018, as fossil-fuel use contributed roughly 37.1 billion tonnes of carbon dioxide to the atmosphere. Emissions are expected to increase globally if left unabated, and ecologists have been trying to better understand how this trend will impact plant ecology. One popular technique, which involves exposing environments to increased levels of carbon dioxide, has been used since the 1990s to study climate change’s impact.

The method, also known as the Free-Air Carbon dioxide Enrichment (FACE) experiment, has offered valuable insight into this matter, but can only give a short-term perspective. As a result, it’s been more challenging for scientists to study the long-term impact that emissions have on plant communities and ecosystems, according to the new study.

FACE facilities, such as the Nevada Desert FACE Facility, creates 21st century atmospheric conditions in an otherwise natural environment. Credit: National Nuclear Security Administration / Nevada Site Office via Wikimedia Commons

Carbon-emitting volcanoes, on the other hand, are often well-studied systems and have been known to emit carbon dioxide for decades to even centuries. For example, experts have been collecting data on gas emissions from Mammoth Mountain, a lava dome complex in eastern California, for almost twenty years. The volcano releases carbon dioxide at high concentrations through faults and fissures on the mountainside, subsequently leaving its forest environment exposed to the emissions. In short, the volcanic ecosystem essentially acts like a natural FACE experiment site.

“This is where long-term localized emissions from volcanic [carbon dioxide] can play a game-changing role in how to assess the long-term [carbon dioxide] effect on ecosystems,” wrote the authors in their published study. Research with longer study periods would also allow scientists to assess climate change’s effect on long-term ecosystem dynamics, including plant acclimation and species dominance shifts.

Through this exploratory study, the researchers involved sought to better understand whether the long-term ecological response to carbon-emitting volcanoes is actually representative to the ecological impact of increased atmospheric carbon dioxide.

Remotely sensed imagery acquired over Mammoth Mountain, showing (a) maps of soil CO2 flux simulated based on accumulation chamber measurements, shown overlaid on aerial RGB image, (b) above-ground biomass (c) evapotranspiration, and (d) normalized difference vegetation index (NDVI). Credit: K. Cawse-Nicholson et al.

To do so, the scientists analysed characteristics of the forest ecosystem situated on the Mammoth Mountain volcano. With the help of airborne remote-sensing tools, the team measured several ecological variables, including the forest’s canopy greenness, height and nitrogen concentrations, evapotranspiration, and biomass. Additionally they examined the carbon dioxide fluxes within actively degassing areas on Mammoth Mountain.

They used all this data to model the structure, composition, and function of the volcano’s forest, as well as model how the ecosystem changes when exposed to increased carbon emissions. Their results revealed that the carbon dioxide fluxes from Mammoth Mountain’s soil were correlated to many of the ecological variables analysed. Additionally, the researchers discovered that parts of the observed environmental impact of the volcano’s emissions were consistent with outcomes from past FACE experiments.  

Given the results, the study suggests that these kind of volcanic systems could work as natural test environments for long-term climate research. “This methodology can be applied to any site that is exposed to elevated [carbon dioxide],” the researchers wrote. Given that some plant communities have been exposed to volcanic emissions for hundreds of years, this method could help paint a more comprehensive picture of our future environment as Earth’s climate changes.

By Olivia Trani, EGU Communications Officer


Cawse-Nicholson, K., Fisher, J. B., Famiglietti, C. A., Braverman, A., Schwandner, F. M., Lewicki, J. L., Townsend, P. A., Schimel, D. S., Pavlick, R., Bormann, K. J., Ferraz, A., Kang, E. L., Ma, P., Bogue, R. R., Youmans, T., and Pieri, D. C.: Ecosystem responses to elevated CO2 using airborne remote sensing at Mammoth Mountain, California, Biogeosciences, 15, 7403-7418,, 2018.

Imaggeo on Mondays: The best of imaggeo in 2018

Imaggeo on Mondays: The best of imaggeo in 2018

Imaggeo, our open access image repository, is packed with beautiful images showcasing the best of the Earth, space and planetary sciences. Throughout the year we use the photographs submitted to the repository to illustrate our social media and blog posts.

For the past few years we’ve celebrated the end of the year by rounding-up some of the best Imaggeo images. But it’s no easy task to pick which of the featured images are the best! Instead, we turned the job over to you!  We compiled a Facebook album which included all the images we’ve used  as header images across our social media channels and on Imaggeo on Mondays blog post in 2018 an asked you to vote for your favourites.

Today’s blog post rounds-up the best 12 images of Imaggeo in 2018, as chosen by you, our readers.

Of course, these are only a few of the very special images we highlighted in 2018, but take a look at our image repository, Imaggeo, for many other spectacular geo-themed pictures, including the winning images of the 2018 Photo Contest. The competition will be running again this year, so if you’ve got a flair for photography or have managed to capture a unique field work moment, consider uploading your images to Imaggeo and entering the 2019 Photo Competition.

A view of the southern edge of the Ladebakte mountain in the Sarek national park in north Sweden. At this place the rivers Rahpajaka and Sarvesjaka meet to form the biggest river of the Sarek national park, the Rahpaädno. The rivers are fed by glaciers and carry a lot of rock material which lead to a distinct sedimentation and a fascinating river delta for which the Sarek park laying west of the Kungsleden hiking trail is famous.


Melt ponds. Credit: Michael Tjernström (distributed via

The February 2018 header image used across our social media channels. The photos features ponds of melted snow on top of sea ice in summer. The photo was taken from the Swedish icebreaker Oden during the “Arctic Summer Cloud Ocean Study” in 2008 as part of the International Polar Year.


Karstification in Chabahar Beach, IRAN. Credit: Reza Derakhshani (distributed via

The June 2018 header image used for our social media channels. The photo was taken on the Northern coast of the Oman Sea, where the subduction of Oman’s oceanic plate under the continental plate of Iran is taking place.


River in a Charoite Schist. Credit: Bernardo Cesare (distributed via

A polarized light photomicrograph of a thin section of a charoite-bearing schist. Charoite is a rare silicate found only at one location in Yakutia, Russia. For its beautiful and uncommon purple color it is used as a semi-precious stone in jewelry.

Under the microscope charoite-bearing rocks give an overall feeling of movement, with charoite forming fibrous mats that swirl and fold as a result of deformation during metamorphism. It may be difficult to conceive, but these microstructures tell us that solid rocks can flow!


Refuge in a cloudscape. Credit: Julien Seguinot (distributed via

The action of glaciers combined with the structure of the rock to form this little platform, probably once a small lake enclosed between a moraine at the mountain side and the ice in the valley.

Now it has become a green haven in the mountain landscape, a perfect place for an alp. In the Alps, stratus clouds opening up on autumn mornings often create gorgeous light display.


Antarctic Fur Seal and columnar basalt Credit: Etienne Pauthenet (distributed via

This female fur seal is sitting on hexagonal columns of basalt rock, that can be found in Pointe Suzanne at the extreme East of the Kerguelen Islands, near Antarctica. This photo was the November 2018 header image for our social media channels.


Silent swamp predator. Credit: Nikita Churilin (distributed via

A macro shot of a Drosera rotundifolia modified sundew leaf waiting for an insect at swamp Krugloe. This photo was the January 2018 header image and one of the finalists in the 2017 Imaggeo Photo Competition.


Once there was a road…the clay wall. Credit: Chiara Arrighi (distributed via

The badlands valley of Civita di Bagnoregio is a hidden natural gem in the province of Viterbo, Italy, just 100 kilometres from Rome. Pictured here is the ‘wall,’ one of the valley’s most peculiar features, where you can even find the wooden structural remains of a trail used for agricultural purposes in the 19th and 20th centuries.


New life on ancient rock. Credit: Gerrit de Rooij (distributed via

“After two days of canooing in the rain on lake Juvuln in the westen part of the middle of Sweden, the weather finally improved in the evening, just before we reached the small, unnamed, uninhabited but blueberry-rich island on which this picture was taken. The wind was nearly gone, and the ragged clouds were the remainder of the heavier daytime cloud cover,” said Gerrit de Rooij, who took this photograph and provided some information about the picture, which features some of the oldest rocks in the world but is bursting with new life, in this blog post.


Cordillera de la Sal. Credit: Martin Mergili (distributed via

The photograph shows the Valle de la Luna, part of the amazing Cordillera de la Sal mountain range in northern Chile. Rising only 200 metres above the basin of the Salar de Atacama salt flat, the ridges of the Cordillera de la Sal represent a strongly folded sequence of clastic sediments and evapourites (salt can be seen in the left portion of the image), with interspersed volcanic material.


Robberg Peninsula – a home of seals. Credit: Elizaveta Kovaleva (distributed via

“This picture is taken from the Robberg Peninsula, one of the most beautiful places, and definitely one of my favorite places in South Africa. The Peninsula forms the Robberg Nature Reserve and is situated close to the Plettenberg Bay on the picturesque Garden Route. “Rob” in Dutch means “seal”, so the name of the Peninsula is translated as “the seal mountain”. This name was given to the landmark by the early Dutch mariners, who observed large colonies of these noisy and restless animals on the rocky cliffs of the Peninsula,” said Elizaveta Kovaleva in this blog post.


The great jump of the Tequendama. Credit: Maria Cristina Arenas Bautista (distributed via

Tequendama fall is a natural waterfall of Colombia. This blog post highlights a Colombian myth about the origins of the waterfall, which is tied to a real climate event.


If you pre-register for the 2019 General Assembly (Vienna, 07 – 12 April), you can take part in our annual photo competition! From 15 January up until 15 February, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at

Looking back at the EGU Blogs in 2018: a competition

Looking back at the EGU Blogs in 2018: a competition

The past 12 months has seen an impressive 382 posts published across the EGU’s official blog, GeoLog, as well as the network and division blogs. From an Easter-themed post on the convection of eggs, features on mental health in academia, commentary on the pros and cons of artificial coral reefs, advice on presenting research at conferencesthrough to a three-part “live-series” on the Arctic Ocean 2018 expedition, 2018 has been packed full of exciting, fun, insightful and informative blog posts.

EGU Best Blog Post of 2018 Competition

To celebrate the excellent display of science writing across the network and division blogs, we are launching the EGU Blogs competition.

We’ve asked our blog editors to put forth their favourite post of the year in the running to be crowned the best of the EGU blogs.  From now until Monday 14th January, we invite you, the EGU Blogs readers, to vote for your favourite post of 2018. Take a look at the poll below with the shortlisted posts, click on the titles to read each post in full, and cast your vote for the one you think deserves the accolade of best post of 2018. The post with the most votes by will be crowned the winner of the public vote. EGU blog editors and staff will also choose their favourites; the post with the most votes from this group will be deemed the winner of the panel vote.

New in 2018

Not only have the blogs seen some great writing throughout the year, they’ve also continued to keep readers up to date with news and information relevant to each of our scientific divisions.

The portfolio of division blogs has expanded this year, with the addition of the Natural Hazards (NH) and the Stratigraphy, Sedimentology and Palaeontology (SSP) blogs last December and March respectively. Since then, they’ve featured posts on many interesting topics, including xenoconformity, research on how bacteria slime can change landscapes, documenting the lives of people exposed to volcanic risk, and geoethics.

Get involved

Are you a budding science writer, or want to try your hand at science communication? All the EGU Blogs, from GeoLog (the official EGU blog), through to the network and division blogs, welcome guest contributions from scientists, students and professionals in the Earth, planetary and space sciences.

It couldn’t be easier to get involved. Decide what you’d like to write about, find the blog that is the best fit for your post and contact the blog editor – you can find all editor details on the individual blog pages. If in doubt, you can submit your idea for a post via the Submit a Post page on GeoLog, or email the EGU Communications Officer, Olivia Trani, who can help with initial enquiries and introduce you to individual blog editors.

Don’t forget to a look at the blog pages for a flavour of the content you can expect from the new, and existing, blogs in 2019. The blogs are also a great place to learn about new opportunities, exciting fields of research and keep up to date with news relating to the upcoming 2019 General Assembly.

Editor’s note on the EGU Best Blog Post of 2018 Competition: The winning post will be that with the most votes on 14th January 2019. The winner will be announced on GeoLog shortly after voting closes. The winning posts will take home an EGU goodie bag, as well as a book of the winners choice from the EGU library (there are up to 3 goodie bags and books available per blog. These are available for the blog editor(s) – where the winning post belongs to a multi-editor blog, and for the blog post author – where the author is a regular contributor or guest author and not the blog editor). In addition, a banner announcing the blog as the winner of the competition will be displayed on the blog’s landing page throughout 2019.

GeoTalk: the climate communication between Earth’s polar regions

GeoTalk: the climate communication between Earth’s polar regions

Geotalk is a regular feature highlighting early career researchers and their work. In this interview, we caught up with Christo Buizert, an assistant professor at Oregon State University in Corvallis, who works to reconstruct and understand climate change events from the past. Christo’s analysis of ice cores from Greenland and Antarctica helped reveal links between climate change events from the last ice age that occurred on opposite ends of the Earth. At this year’s General Assembly, the Climate: Past, Present & Future Division recognized his innovative contributions to palaeoclimatology by presenting him with the 2018 Division Outstanding Early Career Scientists Award.

Christo, thank you for talking to us today! Could you introduce yourself and tell us about your career path so far?

Thanks for having me on GeoTalk! I’m a palaeoclimate scientist working on polar ice cores (long sticks of ancient ice drilled in Greenland and Antarctica), combining data, modeling and fieldwork. My background is in physics, and I did a MSc thesis project on quantum electronics. As you can see, I ended up in quite a different field. After teaching high school for a year in my home country the Netherlands, I pursued a PhD at the Niels Bohr Institute in Copenhagen, Denmark, working on ice cores. I must say, doing a PhD is a lot easier than teaching high school! I have gained a lot of respect for teachers.

After obtaining my PhD I moved to the US for reasons of both work and love (not necessarily in that order). I got a NOAA Climate & Global Change Postdoctoral Fellowship at Oregon State University (OSU). OSU has a great palaeoclimate research group and Oregon is one of the prettiest places on Earth, so the decision to stick around was an easy one.

What inspired you to pursue palaeoclimatology after getting your MSc degree in quantum electronics?

I wish I had a better answer to this question, but the truth is that I was drawn by the possibility of doing fieldwork in Greenland, mainly.

At the General Assembly, you received a Division Outstanding Early Career Scientist Award for your work on understanding the bi-polar phasing of climate change. For those of us who aren’t familiar, could you elaborate on this particular field of study?

The final drill run of the WAIS Divide ice core, with ice from 3,405 m (11,171 ft) depth that has been buried for 68,000 years. (Credit: Kristina Slawny/University of Bern)

During the last ice age (120,000 to 12,000 years ago), the world experienced some of the most extreme and abrupt climate events that we know of, the so-called Dansgaard-Oeschger (D-O) events. About 25 of these D-O events happened in the ice age, and during each of them Greenland warmed by 8 to 15oC within a few decades. Each of the warm phases (called interstadials) lasted several hundreds to thousands of years. Greenland ice cores provide clear evidence for these events.

The abrupt D-O events are thought to be linked to changes in ocean circulation. Heat is transported to the Atlantic Ocean by the Atlantic Meridional Overturning Circulation (AMOC) from the southern hemisphere to the northern hemisphere. The AMOC keeps the Nordic Seas free of sea ice and effectively warms Greenland, particularly during the winter months. However, the strength of this heat circulation went through abrupt changes during the last ice age. Marine sediment data and model studies show that changes to the AMOC strength caused the extreme temperature swings associated with the D-O events.

During weak phases of the AMOC, less heat and salt are brought to the North Atlantic, leading to expansive (winter) sea ice cover and cold conditions in Greenland. These are the D-O cycle’s cold phases, the so-called stadials. And vice versa, during the AMOC’s strong phases, the ocean transports more heat northwards, reducing sea ice cover and warming Greenland. These are the warm (interstadial) phases of the D-O cycle.

When the AMOC is strong, it warms the northern hemisphere at the expense of the southern hemisphere. This inter-hemispheric heat exchange is sometimes referred to as ‘heat piracy,’ since the North Atlantic is ‘stealing’ heat from the southern hemisphere. So when Greenland is warm, we see Antarctica cool, and when Greenland is cold, Antarctica is warming. These opposite hemispheric temperature patterns are called the bipolar seesaw, after the playground toy. Using a new ice core from the West Antarctica Ice Sheet (the WAIS Divide ice core), we were able to study the relative timing of the bipolar seesaw at a precision of a few decades – which is extremely precise by the standards of palaeoclimate research.

An infographic explaining the opposite hemispheric temperature patterns, also known as the bipolar seesaw (Illustration by David Reinert/Oregon State University).

We found that the temperature response to the northern hemisphere’s abrupt D-O events was delayed by about two centuries at WAIS Divide. This finding shows that the effects of these D-O events start in the north, and then are transmitted to the southern high-latitudes via changes in the ocean circulation. If the atmosphere were responsible, transmission would have been much faster (typically within a year or so). State-of-the-art climate models actually fail to simulate this 200-year delay in the Antarctic response, suggesting they are missing (or overly simplifying) some of the relevant physics of how temperature anomalies are propagated and mixed in the global ocean. The timescale of two centuries is unmistakably the signature of the ocean, in my view, and so it is an interesting target for testing models.

At the meeting you also gave a talk about the climatic connections between the northern and southern hemispheres during the last ice age. Could you tell us a little more about your findings and their implications? 

A volcanic ash layer in an Antarctic ice core. Volcanic markers like these were used in the new study to synchronize ice cores from across Antarctica. (Credit: Heidi Roop/Oregon State University)

I presented some recently published work that elaborates on this 200-year delay mentioned earlier. Together with European colleagues, we synchronized five Antarctic ice cores using volcanic eruptions as time markers. This makes it possible to study the timing of the seesaw across the entire Antarctic continent with the same great precision as at WAIS Divide. It turns out that the 200-year delayed oceanic response to the northern hemisphere’s abrupt climate change is visible all over Antarctica, not just in West Antarctica.

But the exciting thing is that by looking at the spatial picture, we detect a second mode of climatic teleconnection, superimposed on the bipolar seesaw we talked about earlier. This second mode has zero-time lag behind the northern hemisphere, suggesting that this mode is an atmospheric teleconnection pattern. In my talk I used postcards and text messages as an analogy for these two modes. The oceanic mode is like a postcard, that takes a long time to arrive in Antarctica (200 years). The atmospheric mode is like a text message that arrives right away.

The atmospheric circulation change (the “text message”) causes a particular temperature pattern over Antarctica, with cooling in some places and warming in others. Think of this as the “fingerprint” of the atmospheric circulation. We then compared the ice-core fingerprint to the fingerprints of several wind patterns seen in modern observations. We found that the so-called Southern Annular Mode, a natural mode describing the variability of the westerly winds circling Antarctica, is the best modern analog for what we see in the ice cores.

An infographic explaining how Earth’s polar regions communicate with each other (Illustration by Oliver Day/Oregon State University)

Another piece of the puzzle is that atmospheric moisture pathways to Antarctica change simultaneously with the atmospheric mode. All this supports the idea that the southern hemisphere’s westerly winds respond immediately to abrupt climate change in the North Atlantic. When D-O warming happens in Greenland the SH westerlies shift to the north, and vice versa, during D-O cooling they shift to the south.

This had been predicted in models, and some limited evidence was available from the WAIS Divide ice core, but the new results provide the strongest observational evidence for this effect. This movement of the westerlies has important consequences for sea ice, ocean circulation, and perhaps even CO2 levels and ice sheet stability. So it really urges us to look at these D-O cycle in a global perspective.

You’ve enjoyed success as a researcher, not least your 2018 EGU Award. As an early career scientist, do you have any words of advice for graduate students who are hoping to pursue a career as a scientist in the Earth sciences?

I’m sure there are many different routes to becoming a successful researcher. Developing your own ideas and insights is key, and the secret to having good ideas is having many ideas, because most of them end up being wrong! So be creative and go out on a limb. I am lucky to have had supervisors who gave me a lot of freedom to explore my own ideas. I would also encourage everybody to develop skills in programming and numerical data analysis, for example in Matlab or python.

Christo Buizert (right) and Didier Roche, President of the Climate: Past, Present & Future Division, (left) at the EGU 2018 General Assembly (Credit: EGU/Foto Pflugel).

Frustrating and unfair as it may be, luck plays an important role in getting your research career started. My main PhD project did not work out, but I had a very productive postdoc that grew out of a side project. I ended up in the right place at the right time, because the WAIS Divide ice core had just been drilled, and I got the privilege to work with some of the best ice core data ever measured.

Research is fundamentally a collaborative enterprise, and so developing a good network of collaborators is maybe the most important thing you can do for yourself. Be generous and helpful to your colleagues, and it will be rewarded.

A career in science sometimes feels like a game of musical chairs, with fewer and fewer positions available as you go along. But if you can hang in there it’s definitely worth it; we have the privilege of thinking about interesting problems, traveling to beautiful places, all while interacting with a global network of fantastic colleagues. Could it get much better?

Interview by Olivia Trani, EGU Communications Officer