GeoTalk: Talking about ‘ocean burps’ with James Rae

GeoTalk: Talking about ‘ocean burps’ with James Rae

Trying to understand the reasons behind the global warming of our climate is a never ending quest for scientists across the geosciences. Scientists often rely on deciphering past change to help us understand, and perhaps predict, what might happen in the future. Many will be familiar with the common saying ‘the past is the key to the future’. This is exactly what James Rae, a research fellow at the Earth & Environmental Sciences Department at the Universty of St. Andrews and this year’s recipient of the Biogeosciences Division Outstanding Young Scientists Award, has been focusing his efforts on. James’ research interest lies in understanding past climate change and he was recognised by the Biogeosciences Division after the publication of his research into ocean ‘burps’ – he and his colleagues found that changes in ocean circulation in the North Pacific caused a massive ‘burp’ of CO2 to be released from the deep ocean into the atmosphere, helping to warm the planet sufficiently to trigger the end of the ice age.

Before we get stuck into the details of your work, could you introduce yourself and tell us a little more about yourself and your career?

My name’s James Rae and I’m a geoscientist at the University of St Andrews. I actually grew up just down the road – in Edinburgh – but only just moved back to Scotland last year, after studies in Oxford, Bristol, and California. The locals tell me that the transition from LA to St Andrews shouldn’t be too tough – apparently St Andrews is “one of the sunniest places in the whole of Scotland”!

I got into geosciences through a love of the outdoors and outdoor sports – mountain biking, surfing, snowboarding, climbing – and though most of my work is now in a super clean lab, I still try to get out in the Scottish Highlands whenever possible.

My career to date has focussed on using geochemistry to reconstruct past environmental change. This means I make measurements of the chemistry of things like shells, fossils, rocks, and ice, which often reflect aspects of the environment they formed in. So by making a series of these measurements on fossil shells back through time we can see how the environment changed in the past. My specialty is using boron in tiny fossil shells, called foraminifera, to reconstruct past CO2 change.

So, ocean ‘burps’? During EGU 2015, you received the Biogeosciences Division Outstanding Young Scientists Award for your study of this unusual phenomenon. Can you tell us more about those?

One of the most interesting things about the ice ages of the last few million years is that they seem to be punctuated with really dramatic rapid climate change. The most recent examples of this are at the end of the last ice age – between about 20 and 10 thousand years ago – where we see intervals of rapid CO2 rise recorded in ice cores. The only place where you can quickly get enough carbon to drive these CO2 changes is the deep ocean. During ice ages we think CO2 gets hidden away beneath the waves, at water depths of 2000 – 5000m, and because the Pacific is so big it’s likely that a lot of this CO2 is stored down there. Other scientists had suggested that this CO2 remerged at the end of the last ice age in the ocean round Antarctica. However my research shows that it could also “burp” out in the North Pacific.

Schematic of how James use boron isotope measurements in foraminifera to reconstruct pH and CO2. Credit: James Rae

Schematic of how James use boron isotope measurements in foraminifera to reconstruct pH and CO2. Credit: James Rae

And how exactly did the release of CO2 in these ‘burps’ affect the climate of the ice age?

Our Pacific “burp” happens right at the beginning of the end of the last ice age – it coincides with the first CO2 rise that heralds the start of the deglaciation. It’s possible that the warming associated with the CO2 “burp” helped push the earth out of it’s ice age, though we need to do more work to test this. But even aside from the CO2, the change in circulation that drove this event had a big influence on local climate. Although most of the Northern Hemisphere is really cold at this time the North Pacific is actually quite warm, which I think is a result of this unusual circulation state.

So, the Northern Hemisphere was very cold at this time; can you describe a little more what the Earth might have looked at during this time and how the local climate of the North Pacific might have been different?

At the end of the last ice age massive ice sheets still covered much of North America and Northern Europe. Over St Andrews the ice was around a kilometre thick. Then, at the beginning of the last deglaciation, in an interval called Heinrich Stadial 1, the ice sheets round the North Atlantic start collapsing. This flooded the North Atlantic Ocean with fresh water and reduced the Atlantic overturning circulation that currently provides heat to this region. As a result much of the Northern Hemisphere got colder. However the climate in the North Pacific does something very different. Likely in response to the big cooling in the North Atlantic, there was a large change in the position of major rain belts, like the Westerly storm track and East Asian Monsoon, and we think this acted to make the North Pacific more salty. This led to a more vigorous overturning circulation in the Pacific, a regional warming, and a burp of CO2 release from the deep sea.

What is the next step, if you like, in order to better understand ocean ‘burps’?

At the moment our key evidence for the North Pacific burp comes from a single sediment core. To test the idea we really need to make more measurements from other cores in this region. Our main evidence for ocean CO2 change also currently comes from records from the deep ocean. One of my PhD students is currently making new records to test how much CO2 made it up from the deep to the surface ocean, and from there to the atmosphere. Finally, with collaborators in Switzerland and the US we’re also testing the physical driving mechanisms of this circulation change using state of the art climate models.

(L) An ocean cruise on which the sediment cores used in the study are collected. (R) Benthic foraminifera - James uses these to make measurements of the chemistry of these to reconstruct past climate change. Credit: James Rae

(L) An ocean cruise on which the sediment cores used in the study are collected. (R) Benthic foraminifera – James uses these to make measurements of the chemistry of these to reconstruct past climate change. Credit: James Rae

You’ve enjoyed success as a researcher, not least your 2015 EGU Award. As an early career researcher, do you have any words of advice for masters and PhD students who are hoping to pursue a career as a scientist in the Earth sciences?

Do what you really enjoy. This feeds in to everything else you do; it means you’ll work hard and carefully in lab, find the reading interesting, and be able to present your work effectively to your colleagues. We do science because we love it, so it’s really important to find topics within your field that you love working on. I think it’s also helpful to find skills to be a specialist in and be known for, but then to try to apply these broadly to big picture questions in geosciences.

Imaggeo on Mondays: The organisation of a river system

Imaggeo on Mondays: The organisation of a river system

The picture shows the Elbe Rivervalley, one of the major rivers of Central Europe. It was taken from the Bastei Bridge close to Rathen, which towers 194 meters above the Elbe River in the state of Saxony in the south-eastern Germany. This region belongs to the national park known as Saxon Switzerland. Together with the Bohemian Switzerland in the Czech Republic, the Saxon Switzerland National Park forms the Elbe Sandstone Mountains, which represents the greatest cretaceous sandstone erosion complex in Europe and is popular with tourists and climbers.

The Elbe basin covers the largest area in Germany (65.5 %) and the Czech Republic (33.7 %). The smaller parts of the basin lie in the Austria (0.6 %) and Poland (0.2 %). It starts in the northern Czech Republic at an elevation of about about 1400 meters above sea level and flows via Bohemian, Germany, and into the North Sea at Cuxhaven. Therefore, the Elbe river system connects four countries as well as large German cities such as Dresden, Wittenberg, Magdeburg and Hamburg.

The sandstone of the Elbe Mountains was formed by accumulation of sands during a marine regression – a process where previously submerged seafloor becomes exposed due to receding ocean waters – (Cretaceous sea) millions of years ago. The varying sandstone formations that make up the mountains represent variations in pressure regime, horizontal structure and fossil content. After the marine regression, the developed sandstone formations were uplifted. The uplifted sandstone formations have been shaped by subsequent chemical and physical erosion and biological processes acting on the rocks. Moreover, the water masses of the Elbe River formed the valleys and streambeds. Therefore, the current state of the landscape of the Elbe Sandstone Mountains is characterised by the changes between plains, ravines, table mountains and rocky regions with undeveloped areas of forest. Human activity also plays an important role in the shaping of the highland region’s landscape as it is affected by settlements, tourisms and climbers.

The image illustrates how the interplay between long-term processes, such as geology, tectonic history, geomorphology, climate, biology and human influence shape landscapes.

By Tatiana Feskova, researcher at the Helmholtz Centre for Environmental Research.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at

Introducing the EGU Executive Office

With so many thinking the EGU’s activities are restricted to the organisation and running of the General Assembly, we thought we’d share a behind-the-scenes peek at the team who works year-round to promote the Earth, ocean and planetary sciences and the work of the members of the Union.

The EGU Office Team. From left to right: Philippe, Sarah, Bárbara, Robert, Laura, Christine and Leslie. Skye, in the front, is the energetic EGU office dog. (Credit: Bárbara Ferreira/EGU).

The EGU Office Team. From left to right: Philippe, Sarah, Bárbara, Robert, Laura, Christine and Leslie. Skye, in the front, is the energetic EGU office dog. (Credit: Bárbara Ferreira/EGU).

At the EGU Executive Office in Munich, Germany, you’ll find the Union’s headquarters. With a team of six employees, which grows to seven when a Union Fellow is appointed, the office runs the day-to-day activities of the EGU. We work year-round on assisting the EGU membership, running media and communications activities and the various EGU-related websites, among other activities. In these, we work in close collaboration with Copernicus, our publisher and conference organiser, and with the EGU Council and the various committees.

EGU Executive Secretary Philippe Courtial manages the office. With eight committees, the Union Council and the Executive board, it is also Philippe’s job to liaise between them all and assist them in their activities. Additionally, Philippe champions the work of the EGU and its members amongst our partner associations and by promoting the Union at conferences worldwide.

Robert Barsch is the Union’s Webmaster and System Administrator. He develops and maintains the EGU’s websites, including Imaggeo and the EGU Blogs, while at the same time taking care of the office’s IT needs. Christine Leidel is in charge of the EGU’s bookkeeping and handling travel expenses, while Leslie Todd provides administrative assistance, organises the Union’s business meetings and handles all membership issues. Leslie is also in charge of maintaining the all-important office coffee and biscuit supplies!

Keeping EGU members and other geoscientists, journalists and the broader public abreast of developments throughout the year falls to the EGU Communications Team. Overall coordination of these activities is the job of EGU Media and Communications Manager Bárbara Ferreira. Bárbara produces the EGU news items and press releases, the EGU’s monthly newsletter, and she also takes on the role of press officer at the annual General Assembly. Barbara is assisted by EGU Communications Officer Laura Roberts, who is in charge of the EGU’s online presence, including social media channels and the blogs. Additionally, she is the point of contact in the office for the Union’s early career scientist (ECS) membership.

The newest member of the EGU Office Team is Sarah Connors, the EGU Science Policy Fellow, who joined us in September this year. Sarah will be working to implement science-policy related activities for EGU scientists. You can learn more about Sarah’s role in this blog post.

To learn more about the EGU’s year-round activities why not visit our website? You’ll be able to find out more about some of our media and communications projects here. Our early career members can find information regarding jobs, career prospects, what’s on for the ECS community at the General Assembly, and much more on our dedicated ECS website.


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