level rise is one of the most challenging impacts of climate change. The
continued rise in sea levels, partially caused by the melting of the ice sheets
of Greenland and Antarctica, will result in large scale impacts in coastal
areas as they are submerged by the sea. Locations not able to bear the costs of
implementing protection and adaptation measures will have to be abandoned,
resulting in social, economic and environmental losses.
most important mitigation goal for sea level rise is to reduce or possibly
revert carbon dioxide (CO2) emissions. Given the time lag between
emission reductions and the impacts of climate change, new adaptation measures
to reduce sea level rise should be proposed, developed and if possible,
A proposal that I developed during my D.Phil degree ten years ago, which resulted in a paper on the Mitigation and Adaptation to Global Change Journal1, shows that submerged barriers in front of ice sheets and glaciers would contribute to reducing the ice melt in Greenland. Edward Byers and I propose the construction of ten barriers at key glaciers in Greenland to stop the flow of warm salty ocean water reaching glaciers in Greenland and Atlantic, which are the main contributors to ice melting. This could reduce sea level rise by up to 5.3 meters at a levelized cost of US$275 million a year. The cost of the barriers is only a fraction of the estimated costs of adaptation measures to sea level rise around the world estimated to be US$1.4 trillion a year by 21002.
barrier consists of several plain sheet modules of marine grade steel around
200 mm thick connected to cylindrical steel tubes with air inside to keep the
barrier floating. The depth of the barriers varies from 30 – 500 meters and the
required length to stop the sea water from entering the fjords, where the
glaciers are located. As no such barrier has been developed before,
we propose three main
steps for the construction of the barrier:
The barrier components
should be transported to the designated location during the summer, when there
is no ocean ice cover and the access to the location of the barrier is less
challenging. Also during the summer, mooring structures should be added.
During the winter, the
barrier is assembled over the frozen ice cover.
During the next summer,
the ice cover will melt again and the barrier will float above the place where
it is should be fixed. The mooring chains attached to the barrier will pull the
barrier into place, using the mooring structures in the ground.
The concept of reducing the contact of seawater and glaciers to reduce ice sheet melting was first published by Moore in Nature3, and Wolovick in The Cryosphere4 with the construction of submerged dams. A graphic representation of the concept is presented in Figure 1. As you can see the barriers should be positioned just after the glacier cavity, where the depth required for the barrier would be the smallest. Our cost analysis shows that using submerged barriers would have one or two orders of magnitude lower costs when compared to submerged dams. Additionally, submerged barriers could be easily removed, if the need arise.
are several issues involving the implementation of these barriers that should
be considered before they are built. The reduction of ice melt in Greenland
glaciers will contribute to an increase in seawater temperature and salinity of
the Arctic Ocean, which will have a direct impact on the region’s biosphere,
climate and ocean currents. The superficial ice cover in the Arctic will be
considerably reduced. This would allow a new maritime route for ships to cross
the Arctic Ocean, increase the absorption of CO2 by the Arctic Ocean,
due to the increase in the ice free surface area and the cold seawater temperature,
and the increase in radiation heat from the Arctic Ocean into space. Ice is a
strong thermal insulator. Without the Arctic Ocean ice cover the temperature of
the region and the heat radiated from the Earth to space will considerably
increase, which could have a higher impact in cooling the Earth than the ice
cover’s albedo effect. Thus, the reduction of the Arctic Ocean ice cover could
contribute to reducing the overall CO2 concentration of the
atmosphere and reducing the Earth’s temperature.
solution, however, should not be used as an excuse to reduce focus on cutting
CO2 emission. If the world continues to warm, not even submerged
barriers in front of glaciers would be able to stop ice sheets melting and sea
Hunt J, Byers E (2018) Reducing sea level rise with submerged barriers and dams in Greenland. Mitigation and Adaptation Strategies for Global Change DOI: 10.1007/s11027-018-9831-y. [pure.iiasa.ac.at/15649]
Jevrejeva JS, Jackson LP, Grinsted A, Lincke D, and Marzeion B (2018) Flood damage costs under the sea level rise with warming of 1.5 ◦C and 2 ◦C. Environmental Research Letters DOI: 10.1088/1748-9326/aacc76
Moore J, Gladstone R, Zwinger T, and Wolovick M (2018) Geoengineer polar glaciers to slow sea-level rise. Nature: /
Wolovick M, Moore J (2018) Stopping the flood: could we use targeted geoengineering to mitigate sea level rise? The Cryosphere DOI: 10.5194/tc-12-2955-2018
By Jessie Jeanne Stinnett, Co-Artistic Director of Boston Dance Theater
I recently had the privilege of artistically collaborating on Dancing with the Future, a project spearheaded by Gloria Benedikt and Piotr Magnuszewski of IIASA with Martin Nowak of Harvard University. The process involved five dancers joining two scientists to create an evening-length performance-debate that toured to Harvard University’s Farkas Hall and the United Nations Conference on Sustainable Development at Columbia University this fall. The essence of this interdisciplinary project was a product of Nowak’s published research on altruism and evolution. Nowak proposes: “Evolution is not only a fight. Not mere competition. Also cooperation, cooperation is the master architect of evolution. Now that we have reached the limits of our planet, can you cooperate with the future?”
What can I do to contribute to a global effort to create sustainable practices that yield cooperation with the future? Why do I dance and what kind of impact does my dancing have on my environment and myself? As a co-artistic director, entrepreneur, choreographer, and performing artist of the young and fast-growing contemporary dance company Boston Dance Theater (BDT), I am turning to projects that are on the innovative cross-section between the arts, technology, and other disciplines because they have the most potential to have meaningful impact on the level of the creative team, the audience, and beyond. I too, am searching for practices and partnerships for BDT that yield pathways for collective problem solving, or ‘super-cooperation’. As Nowak notes, “[evolutionarily speaking] humans are super-cooperators.”
Overall, Dancing with the Future has revealed to me that scientists, dancers, and policymakers can successfully sit at the same table (or in the same theater or conference hall), tackle the same issues, and productively collaborate toward unearthing sustainable solutions.
We all had to be open to compromises — this is not an easy task in a room full of expert-leaders. I set a mantra for myself to remember that we were creating something completely new. Each time my choreographer-dancer brain sent up a red flag, I chose selectively when to share my opinion with the group. I elected to practice the Buddhist teachings of Shunryu Suzuki, captured poetically in Zen Mind, Beginner’s Mind, “In the beginner’s mind there are many possibilities, but in the expert’s there are few.” This choice opened others and myself up to creative and peaceful solutions that I otherwise wouldn’t have seen.
Conversely, I was able to offer constructive solutions at moments when working with the scientific material seemed to overwhelm the studio process, for example, dividing the existing text and music into segments and giving each of those segments a specific choreographic task that related to the content of the scientific text. This was a very simple concept that had to do with pacing and sculpting time. Once we counted out the music, it was easy for us to construct the movement score and see the overall arc of the piece.
I learned not to be afraid of using my voice and also listening deeply. It was, at first, very intimidating to be seated across from experts in fields outside of my own. I learned that scientists and policymakers can understand, respect, and respond to the decisions I make through a process of peaceful negotiation, even when we speak different languages, were born on different continents, and may have varying political opinions. My fear was ultimately unnecessary because the very nature of this project appeals to the humanity in us all.
This form of cross-disciplinary collaboration allows participants to see our own work in a new light and to discover new languages that are exciting because we have co-authored them. For the work to be successful, the dance, science, and debate components must all have equal weight and value. Otherwise, the movement and its choreographic structure becomes the visual representation of the science rather than an equal partner. When that happens, the magic of innovative collaboration falls flat into familiar territory.
During the process, we often referred to this Chinese proverb: “Tell me, and I’ll forget. Show me, and I’ll remember. Involve me, and I’ll understand.” Dancers understand this concept in a very concrete and visceral way. For scientists, policymakers, or the general audience to understand too, they must be involved as much as possible in the process of what we are doing. If we cannot for reasons of practicality, have them with us in the studio, then we must bring them into the process in another way. It is only by involving them as collaborators that we can generate large scale, super-cooperation.
Sometimes it feels like my dancer colleagues and I exist in a vacuum: we rehearse in the confines of the studio and historically perform on stages that make us appear as ‘other’ from the people we are performing for. Western concert dance has received criticism for being an inaccessible art form and according to the 2016 report from The Boston Foundation, is the most under-funded of Boston’s performing arts. Dancers aren’t typically trained to speak about their work, and often have a hard time receiving criticism. Contemporary dance in particular, can be challenging to general audience members because the language of the art and its conceptual frameworks are sometimes not evident in the work itself — many choreographers feel creatively stifled when asked to explain their work in language and wonder why the art work can’t speak for itself.
I have come to learn that these problems are not unique to dance. After our premiere of Dancing with the Future at Harvard University, scientists thanked me for helping them to understand new meaning within the scientific research presented through my performance. Their experience of live performance elicited a keen sense of empathy that drew them into deeper understanding of the scientific findings. This collaboration yielded a tri-fold, reciprocal impact for the artists, for the scientists, and for the public.
Our work helped to bridge the traditional gap between creative team and general audience member. It can be that when a member of the public enjoys a performance, they leave the venue with a good feeling and a nice memory as a souvenir. I believe that our art form has the power to do more — to make a greater impact and to be appreciated as an inherent and necessary aspect of our society and culture.
It is our civic responsibility to continue workshopping solutions toward global cooperation and cooperation with future generations. Dancing with the Future has encouraged me, on a micro scale, that this is a reasonable and plausible endeavor. With continued care, attention toward our common goals, compassion, listening, and risk-taking, we can understand one another through the process of creation regardless of what language we speak or where we were born. The next steps may be small, but nonetheless crucial. Next season, Boston Dance Theater will commission new works by three international choreographers with the stipulation that the pieces must speak to pressing global issues, and cross-disciplinary collaboration will be a cornerstone of that production.
Dancing with the Future has revealed to me that partnerships with super-cooperators such the teams at IIASA and Harvard’s Program for Evolutionary Dynamics can bring meaningful potential to catalyze change in me as an individual and in Boston Dance Theater as an organization, while enabling us to reach our extended communities. I can’t wait for the next project!
Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.
By Marcus Thomson, researcher, IIASA Ecosystems Services and Management Program
While living in Cairo in 2010, I witnessed first-hand the human toll of political and environmental disasters that washed over Africa at the end of the last century. Unprecedented numbers of migrants were pressing into North Africa, many pushed out of their homelands by conflict and state-failure, pulled towards safer, richer, less fragile places like Europe. Throughout Sub-Saharan Africa, climate change was driving up competition for scarce land and water, and raising pressure on farmers to maintain the quantity and quality of their crops.
It is a similar story throughout the developing world, where many farmers do without the use of expensive chemical fertilizer and pesticides, complex irrigation, or boutique seed varieties. They rely instead on traditional land management practices that developed over long periods with consistent, predictable conditions. It is difficult to predict how dryland farmers will respond to climate change; so it is challenging to plan for various social, economic, and political problems expected to develop under, or be exacerbated by, climate change. Will it spur innovation or, as has been argued for the Syrian civil war, set up conflict? A major stumbling block is that the dynamics of human social behavior are so difficult to model.
Instead of attempting to predict farmers’ responses to climate change by modelling human behavior, we can look to the responses to environmental changes of farmers from the past as analogues for many subsistence farmers of the future. Methods to fill in historical gaps, and reconstruct the prehistoric record, are valuable because they expand the set of observed cases of societal-scale responses to environmental change. For instance, some 2000 years ago, an expansive maize-growing cultural complex, the Ancestral Puebloans (APs), was well established in the arid American Southwest. By AD 1000, members of this AP complex produced unique and innovative material culture including the famed “Great Houses”, the largest built structures in the United States until the 19th century. However, between AD 1150 and 1350, there was a profound demographic transformation throughout the Southwest linked to climate change. We now know that many APs migrated elsewhere. As a PhD student at the University of California, Los Angeles, I wondered whether a shift to cooler, more variable conditions of the “Little Ice Age” (LIA, roughly AD 1300 to 1850) was linked to the production of their staple crop, maize.
I came to IIASA as a YSSP in 2016 to collaborate with crop modelers on this question, and our work has just been published in the journal Quaternary International. I brought with me high-resolution data from a state-of-the-art climate model to drive the crop simulations, and AP site information collected by archaeologists. Because AP maize was quite different from modern corn, I worked with IIASA soil scientist Juraj Balkovič to modify the crop simulator with parameters derived from heirloom varieties still grown by indigenous peoples in the Southwest. I and IIASA economic geographer Tamás Krisztin developed a statistical technique to analyze the dynamical relationship between AP site occupation and simulated yield outcomes.
We found that for the most climate-stressed high-elevation sites, abandonments were most associated with increased year-to-year yield variability; and for the least stressed low-elevation and well-watered sites, abandonment was more likely due to endogenous stressors, such as soil degradation and population pressure. Crucially, we found that across all regions, populations peaked during periods of the most stable year-to-year crop yields, even though these were also relatively warm and dry periods. In short, we found that AP maize farmers adapted well to gradually rising temperatures and drought, during the MCA, but failed to adapt to increased climate variability after ~AD 1150, during the LIA. Because increased variability is one of the near certainties for dryland farming zones under global warming, the AP experience offers a cautionary example of the limits of low-technology adaptation to climate change, a business-as-usual direction for many sub-Saharan dryland farmers.
This is a lesson from the past that policymakers might take note of.
 Kelley, C. P., Mohtadi, S., Cane, M. A., Seager, R., & Kushnir, Y. (2015). Climate change in the Fertile Crescent and implications of the recent Syrian drought. Proceedings of the National Academy of Sciences, 201421533.
 Thomson, M. J., Balkovič, J., Krisztin, T., MacDonald, G. M. (2018). Simulated crop yield for Zea mays for Fremont Ancestral Puebloan sites in Utah between 850-1499 CE based on temperature dailies from a statistically downscaled climate model. Quaternary International. https://doi.org/10.1016/j.quaint.2018.09.031
By Sandra Ortellado, 2018 Science Communication Fellow
Around 8,000 kilometers away from Vienna, Austria, hundreds of Arctic coastal communities are at imminent risk from the melting ice and coastal erosion. Indigenous Arctic populations struggle with food insecurity every day, living off small fractions of what their catch would have been only a few years ago. Their culture and their way of life, so dependent on sea ice conditions, are melting away, along with the very root of the Arctic ecosystem.
However, construal level theory, a social psychological theory that describes the extent to which distant things become abstract concepts, tells us that 8,000 kilometers is just far enough for Arctic peoples to lose tangible existence in the minds of urban citizens. Unlike Arctic communities, who experience the direct effects of climate change at each meal, commercialized lower latitude societies don’t have to face the environmental consequences of choosing to drive to the grocery store instead of bike.
Nevertheless, those consequences are very real, even if the impacts on the Arctic and climate system don’t always catch our attention. Sea level will continue to rise for the next several hundred years—it takes 500 years for the deep ocean to adjust to changes at the surface.
On Friday, 22 July, former Chief Scientist of the UK Met Office Dame Julia Slingo and former Chair of the IIASA Council Peter Lemke joined us at IIASA for a joint lecture on climate risk in weather systems and polar regions. The lecture had one underlying theme: in order to make informed decisions on climate change, we need to embrace uncertainty with a broader understanding of what’s possible. That means that the far-away Arctic needs to be seen as nearby and relevant, and that climate change forecasts once seen as ‘uncertain,’ should instead be interpreted as ‘probable.’
“People are often confusing uncertainty with risk. If it’s uncertain they think they don’t really have to think about it. But there is a risk they take if they avoid things,” says Lemke. “a 40% chance could also mean a doubling of the risk, and a doubling of the risk is something that’s easily understood.”
“It’s a matter of how you communicate it,” says Lemke.
Perhaps Hollywood’s obsession with apocalyptic disaster narratives serves some kind of purpose after all—the stories seem outlandish, but films translate them into concepts we can understand and scenes we’re familiar with. It’s hard to picture what it would be like to live in a world that is 2°C warmer, but thanks to Hollywood special effects, we can picture what it would be like if storms of epic proportions engulfed the Statue of Liberty in a gigantic tidal wave.
“We have get down to people’s personal experience. That’s why I’m so against the use of things like global mean temperature, because people can’t relate to that,” says Slingo. “I am very keen on using narrative, but based on science, so people have access to the evidence for why we have this story that we tell about how climate change could affect them personally.”
Of course, we can’t give Hollywood too much credit: these stories are dangerously lacking input from actual climate science. Nevertheless, armed with the forecasting tools and technologies that have advanced so much over the past decade or so, we can counter uncertainty and get a better understanding of the risks we face. For example, using improved computer models and satellites that determine the age and thickness of ice, we can determine the rates of receding ice, and how much that will affect sea level rise in coastal communities.
Likewise, social media makes it easy to transmit information rapidly to a large audience that might not have been reachable otherwise. Reaching people where they are is of paramount importance—while scientists can put painstaking effort into presenting the most accurate, unbiased account of probable risks, this is just one facet of any given decision. In the end, it is the public and the policymakers that represent them that must make the decision about what actions to take, based on a complete narrative that includes the socioeconomic and cultural factors involved.
“It’s all about dialogue at the end of the day. One of the things I learned as MET office chief scientist was that based on the evidence I was giving to government, you would think that the policy would be quite clear,” says Slingo. “But there are other aspects to take into consideration, such as unemployment or other policy implementation capacities and societal implications.”
That’s why Lemke and Slingo both make huge efforts to communicate with the public, especially with the impressionable, optimistic, social media savvy and politically mobilizing younger generations. From their interactions and outreach with the public, Lemke and Slingo know that once you put climate change in proximity and translate science into narratives that are relevant to the lives of individual citizens, the public does care about climate change. They want to know more, and they want to do something about it.
When it comes to environmental advocacy, education is power, especially when it translates the high-end risk probabilities of climate science into relatable narratives. For Lemke and Slingo, that creates a huge opportunity for scientists of all backgrounds.
“I don’t think climate change has to be depressing. It’s a fantastic opportunity for a whole generation of scientists and engineers to tackle a great problem,” says Slingo. “I actually have the confidence that we’ll solve it.”
On 14 and 15 May, Vienna hosted two important events within the frame of the world energy and climate change agendas: the Vienna Energy Forum and the R20 Austrian World Summit. Since I had the pleasure and privilege to attend both, I would like to share some insights and relevant messages I took home with me.
To begin with, ‘renewable energy’ was the buzzword of the moment. Renewable energy is not only the future, it is the present. Recently, 20-year solar PV contracts were signed for US$0.02/kWh. However, renewable energy is not only about mitigating the effects of climate change, but also about turning the planet into a world we (humans from all regions, regardless of the local conditions) want to live in. It is not only about producing energy, about reaching a number of KWh equivalent to the expected demand–renewables are about providing a service to communities, meeting their needs, and improving their ways of life. It does not consist only of taking a solar LED lamp to a remote rural house in India or Africa. It is about first understanding the problem and then seeking the right solution. Such a light will be of no use if a mother has to spend the whole day walking 10 km to find water at the closest spring or well, and come back by sunset to work on her loom, only to find that the lamp has run out of battery. Why? Because her son had to take it to school to light his way back home.
This is where the concept of ‘nexus’ entered the room, and I have to say that more than once it was brought up by IIASA Deputy Director General Nebojsa Nakicenovic. A nexus approach means adopting an integrated approach and understanding both the problems and the solutions, the cross and rebound effects, and the synergies; and it is on the latter that we should focus our efforts to maximize the effect with minimal effort. Looking at the nexus involves addressing the interdependencies between the water, energy, and food sectors, but also expanding the reach to other critical dimensions such as health, poverty, education, and gender. Overall, this means pursuing the Sustainable Development Goals (SDGs).
Another key word that was repeatedly mentioned was finance. The question was how to raise and mobilize funds for the implementation of the required solutions and initiatives. The answer: blended funding and private funding mobilization. This means combining different funding sources, including crowd funding and citizen-social funding initiatives, and engaging the private sector by reducing the risk for investors. A wonderful example was presented by the city of Vienna, where a solar power plant was completely funded (and thus owned) by Viennese citizens through the purchase of shares.
This connects with the last message: the importance of a bottom-up approach and the critical role of those at the local level. Speakers and panelists gave several examples of successful initiatives in Mali, India, Vienna, and California. Most of the debates focused on how to search for solutions and facilitate access to funding and implementation in the Global South. However, two things became clear. Firstly, massive political and investment efforts are required in emerging countries to set up the infrastructural and social environment (including capacity building) to achieve the SDGs. Secondly, the effort and cost of dismantling a well-rooted technological and infrastructural system once put in place, such as fossil fuel-based power networks in the case of developed countries, are also huge. Hence, the importance of emerging economies going directly for sustainable solutions, which will pay off in the future in all possible aspects. HRH Princess Abze Djigma from Burkina Faso emphasized that this is already happening in Africa. Progress is being made at a critical rate, triggered by local initiatives that will displace the age of huge, donor-funded, top-down projects, to give way to bottom-up, collaborative co-funding and co-development.
Overall, if I had to pick just one message among the information overload I faced over these two days, it would be the statement by a young fellow in the audience from African Champions: “Africa is not underdeveloped, it is waiting and watching not to repeat the mistakes made by the rest of the world.” We should keep this message in mind.
How did your scientific career evolve into climate change and ecosystem ecology? I studied environmental science in Spain and then I went to Australia, where I started working on free-air CO2 enrichment, or FACE experiments. These are very fancy experiments where you fumigate a forest with CO2 to see if the trees grow faster. In 2014 I moved to London for my PhD project. There, instead of focusing on one single FACE experiment, I collected data from all of them. This allowed me to make general conclusions on a global scale rather than a single forest.
You recently published a paper in Science magazine. Could you summarize the main findings? We found that we can predict how much CO2 plants transfer into growth through the CO2 fertilization effect, based on two variables—nitrogen availability and the type of mycorrhizal, or fungal, association that the plants have. The impact of the type of mycorrhizae has never been tested on a global scale—and we found that it is huge. I think it’s fascinating that such tiny organisms play such a big role at a global scale on something as important as the terrestrial capacity of CO2 uptake.
How did you come up with the idea? One random day in the shower? Long story short, researchers used to think that plants will grow faster, and take up a lot of the CO2 we emit. They assumed this in most of their models as well. But plants need other elements to grow besides CO2. In particular, they need nitrogen. So scientists started to question whether the modeled predictions overestimated the CO2 fertilization effect, because the models did not consider nitrogen limitation. To find out, I analyzed all the FACE experiments and indeed I saw that in general plants were not able to grow faster under elevated CO2 and nitrogen limitation. However, in some cases plants were able to take advantage of elevated CO2 even under nitrogen limitation. I grouped together the experiments where plants could grow under nitrogen limitation and after a lot of reading I saw what they had in common: the type of fungi! It turned out that one type of mycorrhizae is really good at transferring large quantities of nitrogen to the plant and the other type is not.
How did that feel? Awesome! When I saw the graph, I knew: this is going to be important. Of course, after this, my coauthors helped me to polish the story. Without them, the conclusions would not be as robust and clear.
So how does this process work? Where do the fungi get the nitrogen from? Particular soils might have a lot of nitrogen, but the amount available for plants to absorb might be low. Also, plants have to compete with non-fungal microorganisms for nitrogen. So if there is not much there, the microorganisms take it all. It’s called immobilization. Instead of mineralizing nitrogen, they immobilize it so that plants cannot take it up, at least not in the short term. Some types of fungi are much more efficient in accessing nitrogen, and associated with roots they allow plants to overcome limitations.
What is the impact of your findings? Plants currently take up 25-30% of the CO2 we emit, but the question is whether they will be able to continue to do so in the long term. Our findings bring good and bad news. On the one hand, the CO2 fertilization effect will not be limited entirely by nitrogen, because some of the plants will be able to overcome nitrogen limitation through their root fungi. But on the other hand, some plant species will not be able to overcome nitrogen limitation.
There was a big debate about this. One group of scientists believed that plants will continue to take up CO2 and the other group said that plants will be limited by nitrogen availability. These were two very contrasting hypotheses. We discovered that neither of the hypotheses was completely right, but both were partly true, depending on the type of fungi. Our results could bring closure to this debate. We can now make more accurate predictions about global warming.
What will you do at IIASA and how will you link it to your PhD? I want to upscale and quantify how much carbon plants will take up in the future. If we are to predict the capacity of plants to absorb CO2, we need to quantify mycorrhizal distribution and nitrogen availability on a global scale. We are updating mycorrhizal distribution maps according to distribution of plant species. We know for instance that pines are associated with ectomycorrhizal fungi and always will be. To quantify nitrogen availability we use maps of different soil parameters that are available on a rough global scale.