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 Farid Karimi, independent researcher and IIASA alumnus
There is consensus that the current trend of energy consumption growth and CO2 emissions cannot continue if global warming is to be tackled. Many countries have considered carbon capture and storage (CCS) for addressing climate change. CCS is a technology that mitigates CO2 emissions by removing CO2 from the atmosphere and storing it in carbon sinks–in other words, in an environment or reservoir that has the ability to “store” CO2–such as depleted oil and gas fields.
The Intergovernmental Panel on Climate Change has emphasised that it is not possible to ‘limit likely warming to below 2°C if bioenergy, CCS, and their combination (BECCS) are limited’, while the International Energy Agency has stated that ‘CCS must be part of a ‘strengthened global climate response’. Even if one does not consider the energy sector, CCS is almost the only way to reduce CO2 from the cement and steel industries. Nonetheless, CCS is a controversial technology. There is notable opposition to and different perceptions of the technology among stakeholders and we also know that the reaction of the public to CCS will considerably affect the development of the technology in democratic countries. Therefore, it is important to understand these diverse perceptions and their roots.
Photo by Thomas Hafeneth on Unsplash
In our research, we looked at this controversial technology from a cross-cultural perspective. Previous research has identified general and local mechanisms in how the general public reacts to CCS and researchers have also noticed that there are differences between countries, but the effects of cross-cultural differences had not previously been explored in detail. In our study, which was recently published in the International Journal of Greenhouse Gas Control, we argue that it is crucial to understand how public perceptions of a particular technology emerge and form in their individual contexts or how perceptions are embedded in large-scale cultural frameworks.
Our results show that the effects of individual level variables such as familiarity with technology, or sociodemographic variables such as education, are important, but their effects are likely mediated and confounded by the cultural setting. We found that in parallel with other factors such as trust, cultural dimensions such as uncertainty avoidance and the society’s short-term or long-term orientation affect risk perception. Uncertainty avoidance can be described as the extent to which members of a society feel uncomfortable with uncertain, unknown, ambiguous, or unstructured situations. Long-term orientation on the other hand, refers to a society that fosters virtues and is oriented towards future rewards, in particular perseverance and thrift.
High uncertainty avoidance, for instance, leads to higher risk perception because among nations with a strong uncertainty avoidance index, there is a mentality of “what is different is dangerous”. Moreover, countries that demonstrate a long-term orientation might express a higher level of risk perception concerning the technology because people from these countries place more value on thrift, which implies being more careful about investing in risky or uncertain matters. In addition, investment in real estate is a notable feature of such societies, and this is closely tied to the issue of NIMBY – an acronym for the phrase “not in my back yard”, denoting opposition by residents to a proposed development in their area – which is one of the most important controversies related to CCS. For example, Germany has a very high long-term orientation, so Germans have serious concerns about the effect of CCS on the real estate market and about having CCS facilities in their region.
All in all, our work provides a framework to understand why and how societies challenge the technology. Cultural differences and lack of consideration for them have in the past caused the failure of negotiations or implementation of some projects. Our study is a contribution to the field and could be used to understand how cross-cultural differences operate in the realm of sustainable energy technology.
By Reinhard Mechler, Deputy Program Director, IIASA Risk and Resilience Program
IPCC Special Report on Global Warming of 1.5°C
The Intergovernmental Panel on Climate Change (IPCC) just approved its Special Report on Global Warming of 1.5°C (SR15). It took long hours of discussions between the body of authors and representatives from about 130 IPCC member states gathered at the approval session in Korea, to get the highly anticipated report accepted. The report was requested by parties to the United Nations Framework Convention on Climate Change (UNFCCC) as set out in the Paris Agreement in 2015, that urged parties to limit warming to “well below” 2°C and pursue efforts towards 1.5°C of warming above pre-industrial levels. Countries that are severely vulnerable to climate change such as small-island states, expressed a particular need for the report. The drafted text of the summary for policymakers (SPM) remained largely intact throughout the approval session and the science was well respected by the parties (as has generally been the case for the IPCC). This bodes well for the IPCC’s process of reporting the most up to date information on climate science to national and international decision makers who closely review and comment on drafts of texts throughout the writing process.
The report, composed of five chapters and the SPM, discusses among other topics whether the Paris target of 1.5°C above pre-industrial temperature is still achievable; what the risks we face are at 1.5°C and 2°C of warming; what this will mean in terms of mitigation and adaptation; and what the synergies are between mitigation, adaptation and the Sustainable Development Goals (SDGs).
Below my take on how the SR15 answers some of these questions:
A stark warning… and indeed half a degree does make a difference
The world is on its way to breaching 1.5°C by around the 2040s, which will lead to further warming if current greenhouse gas emissions trends prevail and current nationally determined contributions (NDCs) are not upgraded. Warming can still be stabilized at 1.5°C, but it is an ambitious target that depends on halving emissions over the next 10 years and becoming carbon-neutral by 2050.
The report shows that we are already seeing serious consequences of a 1°C warming in the form of significant increases in some weather-related extreme events (such as the frequency, intensity, and/or amount of heavy precipitation in several regions), exacerbated sea level rise, and other effects on important terrestrial and oceanic systems. In terms of future warming, the report shows that a half-degree change, which we have actually seen over the last 50 years, indeed makes a difference. Risks will be higher than today at 1.5°C and will further increase at 2°C (and beyond).
Adaptation and its limits: A need for transformation?
In light of the above, adaptation is essential and needs to be ramped up. However, for the first time, the IPCC presents evidence on hard and soft limits to adaptation, of which some would already be reached at 1.5°C. Statement B6 of the SPM reads: “Most adaptation needs will be lower for global warming of 1.5°C compared to 2°C (high confidence). There are a wide range of adaptation options that can reduce the risks of climate change (high confidence). There are limits to adaptation and adaptive capacity for some human and natural systems at global warming of 1.5°C, with associated losses (medium confidence).”
So, what should we do in terms of adaptation in light of pervasive risks becoming increasingly severe and ultimately breaching adaptation limits? Statement A3.3 of the SPM suggests that, “Future climate-related risks would be reduced by the upscaling and acceleration of far-reaching, multi-level, and cross sectoral climate mitigation and by both incremental and transformational adaptation (high confidence).”
Throughout the document, the SR15 discusses what is needed in terms of standard adaptation (incremental) and transformational adaptation. An example of incremental adaptation is to continue building sea walls to manage increasing flooding from sea level rise. Adapting community and regional planning so that people, key assets, and buildings are moved out of harm’s way on the other hand, would be rather transformational–and often have a holistic and systemic component. The report also shows that more effort will be needed to better understand what transformational risk management processes may entail concretely.
Transformation: What does it take?
Transformational adaptation may not always be needed uniformly across the globe, but as the report shows, communities in regions vulnerable to sea-level rise risk, flooding, heat, and drought already clearly need significant support, and in a 1.5°C or 2°C world, much more would be needed. The report also shows that increasing investment in physical and social infrastructure is a key enabler of necessary transformations that enhance the resilience of communities and societies. Upgrading climate adaptation efforts will be fundamental to absorbing some climate change impacts and not critically affecting the achievement of the SDGs. What is more, the SR15 points out that the coordinated pursuit of climate resilience and development is the way forward to achieving the ambitious mitigation and adaptation targets set out, while seeking achievement of development goals such as those formulated in the 17 SGDSs.
Among others, three main implications for adaption (and climate risk) science, policy, and practice can be drawn:
Climate-related risks are becoming pervasive and significant with climatic change: The Paris call for limiting warming to 1.5°C should be heeded and remain the target for ambitious climate mitigation policy in order to avoid some risks from becoming irreversible and hard adaptation limits manifesting themselves.
Climate-related risks are becoming pervasive due to gaps in human, physical, financial, natural, and social capacity/capitals, and increased and targeted investments to strengthen these will be needed to push soft adaptation limits out.
Systemic approaches are needed to tackle high-level risks and consider synergies between adaptation, mitigation, and the SDGs as standard adaptation and disaster risk reduction may not be enough. Transformational approaches requiring large-scale and systemic change are useful in this regard.
The open question…
The final, open question for all of us is of course whether the report can be more than another wake-up call and truly be a game-changer for limiting warming to 1.5°C while ramping up adaptation efforts. The science is there. Broad-based dissemination efforts with policymakers and advisors, experts, the private sector, and civil society are being rolled out. The political will to live up to the massive mitigation and adaptation challenges needs to follow now. Little time remains, and if we truly want to limit warming to 1.5°C and mitigate the associated risks, we need to take decisive and bold steps towards carbon-neutrality and climate-resilience now.
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 Sandra Ortellado, IIASA 2018 Science Communication Fellow
If fashion is the science of appearances, what can beauty and aesthetics tell us about the way we perceive the world, and how it influences us in turn?
From cognitive science research, we know that aesthetics not only influence superficial appearances, but also the deeper ways we think and experience. So, too, do all kinds of creative thinking create change in the same way: as our perceptions of the world around us changes, the world we create changes with them.
From the merchandizing shelves of H&M and Vero Moda to doctoral research at the Faculty of Information Technology at the University of Jyväskylä, Finland, 2018 YSSP participant Laura Mononen has seen product delivery from all angles. Whether dealing with commercialized goods or intellectual knowledge, Mononen knows that creativity is all about a change in thinking, and changing thinking is all about product delivery.
“During my career in the fashion and clothing industry, I saw the different levels of production when we sent designs to factories, received clothing back, and then persuaded customers to buy them. It was all happening very effectively,” says Mononen.
But Mononen saw potential for product delivery beyond selling people things they don’t need. She wanted to transfer the efficiency of the fashion world in creating changes in thinking to the efforts to build a sustainable world.
“Entrepreneurs make change with products and companies, fashion change trends and sell them. I’m really interested in applying this kind of change to science policy and communication,” says Mononen. “We treat these fields as though they are completely different, but the thing that is common is humans and their thinking and behaving.”
Often, change must happen in our thinking first before we can act. That’s why Mononen is getting her doctorate in cognitive science. Her YSSP project involved heavy analysis of systems theories of creativity to find patterns in the way we think about creativity, which has been constantly changing over time.
In the past, creativity was seen as an ability that was characteristic of only certain very gifted individuals. The research focused on traits and psychological factors. Today, the thinking on creativity has shifted towards a more holistic view, incorporating interactions and relationships between larger systems. Instead of being viewed as a lightning bolt of inspiration, creativity is now seen as more of a gradual process.
New understandings of creativity also call on us to embrace paradoxes and chaos, see ourselves as part of nature rather than separate from it, experience the world through aesthetics, pay careful attention to our perception and how we communicate it, and transmit culture to the next generation.
Perhaps most importantly, Mononen found in her research that the understanding of creativity has changed to be seen as part of a process of self-creation as well as co-creation.
“The way we see creativity also influences ourselves. For example if I ask someone if they are creative, it’s the way they see themselves that influences how creative they are,” says Mononen. “I have found that it’s more crucial to us than I thought, creativity is everywhere and it’s everyday and we are sharing our creativity with others who are using that to do something themselves and so on.”
This means on the one hand that we use our creativity to decide who we are and how we see the world around us for ourselves. But it also means that the outcomes and benefits of creativity are now intended for society as a whole rather than purely for individuals, as it was in the past. It may sound like another paradox, but being able to embrace ambiguity and complexity and take charge of our role in a larger system is important for creating a sustainable future.
“From the IIASA perspective this finding brings hope because the more people see themselves as part of systems of creating things, the more we can encourage sustainable thinking, since nature is a part of the resources we use to create,” says Mononen.
Mononen says a systems understanding of creativity is especially important for people in leadership positions. If a large institution needs new and innovative solutions and technology, but doesn’t have the thinking that values and promotes creativity, then the cooperative, open-minded process of building is stifled.
Working in both the fashion industry and academic research, Mononen has encountered narrow-minded attitudes towards art and science firsthand.
“Communicating your research is very difficult coming from my background, because you don’t know how the other person is interpreting what you say,” says Mononen. “People have different ideas of what fashion and aesthetics are, how important they are and what they do. Additionally, scientific concepts are used differently in different fields.”
“We are often thinking that once we get information out there, then people will understand, but there are much more complex things going on to make change and create influence in settings that combine several different fields.” says Mononen.
For Mononen, the biggest lesson is that creativity can enhance the efforts of science towards a sustainable world simply by encouraging us to be aware of our own thinking, how it differs from that of others, and how it affects all of us.
“When you become more aware of your ways of thinking, you become more effective at communicating,” says Mononen. “It’s not always that way and it’s very challenging, but that’s what the research on creativity from a systems perspective is saying.”
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 Melina Filzinger, IIASA Science Communication Fellow
Yuping Bai is a participant of the IIASA Young Scientists Summer Program (YSSP) and a first year PhD candidate at the Chinese Academy of Sciences’ Institute of Geographic Sciences and Natural Resources Research. She is working with the Intergovernmental Panel on Climate Change (IPCC), the leading international body for the assessment of climate change, as a chapter scientist for their Special Report on Climate Change and Land. I recently had the chance to talk to her about her engagement as a chapter scientist.
What is the aim of the IPCC special report on climate change and land?
Compared to the IPCC comprehensive assessment reports, this special report really focuses in depth on the linkages and inter-relationship between climate change, land use, and food security. It aims to propose sustainable land-based solutions towards climate change mitigation and adaptation efforts. We all know that climate change is an important issue and the connections between climate change and land use change are extremely complex. The report will include many different topics like land degradation, desertification, greenhouse gas fluxes and food security. Understanding the links between these diverse issues is particularly important for informing decision making by governments, as well as private sectors, to address challenges in land use change and governance.
What is a chapter scientist?
Chapter scientists are early-career researchers that support the development process of the individual report chapters. IPCC asked for volunteers who are required to dedicate at least one-third full time equivalent over a 2.5-year period while working from their home institutions. The chapter scientists were chosen based on expertise, motivation, time availability, and experience in working in a multi-cultural context. There are ten chapter scientists in total working on the report, one or two for each chapter.
How do you contribute to the report?
I am assigned to Chapter 1, which provides the framing and context for the report. Part of my job has been organizational tasks, for example managing our referencing system, scheduling online meetings, tracking down key literature, assisting in the design and development of figures and tables, and assisting in compiling, revising, and organizing chapter contributions. On the other hand, I have also been involved in developing the overall concept of our chapter and can voice my ideas and express my views. Chapter 1 raises the key issues related to land use and sustainable land management for climate adaptation and climate resilience, and provides the concepts and definitions needed to understand the rest of the report.
In fact, many of these topics are closely related to my PhD research and my YSSP project. The YSSP experience significantly broadened my knowledge on climate change and land related topics, and at the same time deepened my understanding of the cross-scale complexity of the issues. After three months, I feel that I’m much better equipped to contribute to the future work for the chapter.
Why did you decide to volunteer so much of your time?
As a chapter scientist I have the chance to participate in discussions on some of the most pressing and important issues in the world. I also have the unique possibility to work with some of the world leading scientists in their respective fields. Therefore, I think it’s an important opportunity to make contacts and to gain insight into the work of the IPCC.
What has your experience been so far?
I’m the youngest one of the chapter scientists, so I felt a bit overwhelmed at first, particularly as I was suddenly rubbing shoulders with some of the brightest, most established academics and researchers on the planet. In this first half year, I attended the second lead author meeting and have been involved in the first draft of the report. During busy periods leading up to key deadlines, such as the submission of the drafts, my hours peaked, and the pressure built. But don’t let this frighten you. It is possible to learn on the job! It helped that everyone made me feel so welcome and valued. I have definitely learned a lot. My research is very specialized, and my work with the IPCC has helped me gain a broader view on climate change and the problems that are connected to it.
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.