Apr 30, 2014 | Alumni, Food & Water
Eric F. Wood is a hydrologist at Princeton University, well-known for his work in hydrology, climate, and meteorology. He worked as a research scholar in IIASA’s Water program from 1974 to 1976. On 30 April, 2014, he received the European Geophysical Union’s Alfred Wegener Medal in Vienna, Austria.

Eric F. Wood (Credit: Princeton University)
IIASA: How did you get interested in hydrology? What drew you to the field?
EW: I came to IIASA after I finished my doctorate at MIT. I worked in the areas of system analysis and statistics related to water resources. During my first sabbatical leave at the Institute of Hydrology in the UK (now the Center for Hydrology and Ecology), I started to collaborate with Keith Beven on hydrological modeling, which started my transition towards the physical side of the water cycle from the policy and systems analysis side.
A few years later, Robert Gurney, then at NASA and now at the University of Reading (UK), asked if I would be on the Science Advisory Committee for NASA’s Earth Observing System (EOS), which was just starting to be planned. This started my research activities in terrestrial remote sensing. Over the next 25 years these elements have played heavily in my research activities.
What have been the biggest changes in hydrology and earth science over your career – either in terms of new understandings, or in how the science is done?
I can name three huge changes, all inter-connected: One is the increase in computational resources. High performance computing—petabyte computing using 500,000+ cores—is now available that allows us to simulate the terrestrial water and energy budgets using physics resolving land surface models at 100m to 1km resolutions over continental scales, and soon at global scales. The second big change is the availability of remotely sensed observations. There are satellite missions that have lasted far beyond their planned lifetimes, such as the NASA EOS Terra mission, where we now have over 15 years of consistent observations. These observations have been reprocessed as algorithms have improved so we can now use the information to understand environmental change at regional to global scales. The third major shift has been computer storage. Large amounts are available at low prices. We have about 500 Terabytes of RAID storage, and can acquire 150TB for about $10,000 or less. This allows us to store model simulations, remote sensing data, and do analyses that were once impossible. Together, these three changes have transformed my field, and the field of climate change related to terrestrial hydrology. Going forward, we have the data, the projections and analytical tools to look at water security in the 21st Century under environmental change.
What insights has remote sensing brought to hydrology?
Remote sensing offers a global consistency that is unavailable with in-situ observations, and offers observations over regions without ground data. This permits us to analyze hydrologic events such as droughts within a global context, and relate these hydrologic events to other drivers like ENSO (tropical Pacific sea surface temperature anomalies) that affect weather and seasonal climate patterns.

Wood’s work has focused in part on drought and climate change. Badwater, California, a huge salt flat drainage system for the Death Valley desert. Credit: Carolina Reyes (distributed via imaggeo.egu.eu)
What do you see as the key questions currently facing water resources?
The biggest question I see over the next decades is how water security will be affected by environmental change. By environmental change I mean climate change, global urbanization, increasing demand for food, land use and land cover change, pollution, etc. Water security is coupled to food and energy security, and water security is and it is intrinsically linked to the climate system and how that may be changing.
How did IIASA influence your research interests or career?
I made many friendships during my stay at IIASA and I was exposed to world-class research and researchers. This helped me in thinking about important research questions and the types of problems and research that will have impact.
What do you think is the role for IIASA in the worldwide research community?
There are many answers to this question. IIASA plays an important role in providing critical scientific information and analyses related to global issues that go beyond countries – transboundary analyses, and therefore that can provide the scientific basis for global policies. There is an urgent need for more global policies on environmental change and adaptation, food and water security, and environmental refugees, to name just a couple examples in my area.
IIASA has also developed scientific methods and data that can be applied by various groups. For example, IIASA’s world renowned integrated assessment models have been used in climate change modeling for the IPCC and Coupled Model intercomparison Project (CMIP).
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.
Apr 23, 2014 | Alumni, Energy & Climate
By Alan McDonald, IIASA Alumnus (1979-82 and 1997-2000) and member of the IIASA Alumni Advisory Board
I stumbled on IIASA in 1975. I was 24 and working for General Electric’s Fast Breeder Reactor Department. I was supposed to figure out how safe General Electric should make its new breeder reactor, a type of nuclear reactor (The project later died when Jimmy Carter came to the White House and the uranium price plummeted). We researched what was going on around the world on determining acceptable risks. The best stuff was coming from this place outside Vienna called the International Institute for Applied Systems Analysis. We didn’t know IIASA was only two years old. We only knew its papers on determining acceptable risks were better than anyone else’s.
In 1977 I look a leave from GE to go to the Kennedy School of Government at Harvard. In my second year I was a teaching assistant for Howard Raiffa and took his seminar on the art and science of negotiation. After graduation, I asked if I could get a job at IIASA. Perhaps in an administrative capacity, he thought, since I didn’t have a PhD. If I wrote a page about why IIASA should consider me, he might forward it to Laxenburg.
Wolf Häfele hired me for what was then called the Energy Systems Program (ENP). It was 1979, six years after the Arab oil embargo, the creation of OPEC, and an explosion of energy studies in the US and other oil importing countries. All those national studies projected national oil demands exceeding supplies by varying amounts depending on the policies being modeled. Then they labeled the unmet demand “imports.” IIASA was the first to check if all those imports might add up to more than the oil exporters could export, and what might be done about it if they did. In addition, ENP developed the energy supply model MESSAGE, now used in multiple national and international studies. Cesare Marchetti’s logistic model taught humility about dreams of quick policy-driven transitions away from oil. And ENP still had some of the world’s best work on risk acceptance — which had the added benefit of provoking Mike Thompson to analyze the issue through the lens of cultural anthropology and generate a whole new set of useful insights.
I met my wife, Sue, at IIASA. She was in Personnel and, when I arrived, briefed me about leave slips and all the rest. Part way through, she stopped. “You’re not listening,” she said. “If I have questions, I can come back,” said I. I did, and I did.
Two and a half years later we left IIASA, got married and did a 5-month road-trip honeymoon around the US on the theory it might be another 50 years before we were again so unburdened with obligations (right so far). The trip ended in Cambridge, Massachusetts. The US membership in IIASA was being exiled from Washington to Cambridge due to Dick Pearle’s and President Reagan’s animosity. I joined up to pitch IIASA’s virtues to foundations, US corporations and anyone who’d listen in Washington. In pitching IIASA’s virtues, there was a lot to work with.
Now there’s even more.
IIASA Alumni Day will take place on April 29, 2014, and we are inviting alumni to send their memories and photos of their time at IIASA. For more alumni memories, see the IIASA Alumni Web page.

From left, Alan McDonald, Sue (Buffery) McDonald, David McDonald (no relation), Walter Foith, Linda Foith, and Bill Godwin-Toby taking a break during the July 4th games, 1980.
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.
Apr 15, 2014 | Energy & Climate, Science and Policy
By Jessica Jewell, Research Scholar, IIASA Energy Program
How would action to mitigate climate change affect energy security for countries around the world? In two recent studies that I worked on with colleagues in IIASA’s Energy Program and three other European research centers, we explored this question under a range of different policy scenarios. We found that in the long term – 40 to 90 years from now – climate policies would actually benefit energy security. Our studies showed that policies to limit climate change would lead to lower oil and gas trade. Since both of these fuels are supplied by only a few countries, shifting to other fuels could alleviate concerns for countries which import these energy sources. Our research also shows that a climate-friendly energy system would be more resilient to energy supply and price shocks as well as economic and fossil resource uncertainty.

An oil rig off the coast of California. New research shows that transitioning away from fossil fuels would be good for long-term energy security. Credit: Arby Reed via Flickr: Creative Commons License
Taking action to slow climate change requires a massive change in how our society supplies and uses energy. But achieving a low-carbon energy system – one which releases less greenhouse gases – will only be possible if it doesn’t compromise national energy priorities. One of the main energy priorities for decision-makers is ensuring energy security – that is, the stability and resilience of energy supply and infrastructures.
In our studies, published in Energy Policy and Climatic Change we aimed to figure out whether phasing out fossil fuels would alleviate energy dependence concerns or if decarbonization would simply replace existing vulnerabilities with new ones. Intuitively, addressing climate change would mean increasing renewables and would clearly lead to lower energy dependence. After all, Putin doesn’t own the wind. But would climate policies lead to some unintended consequences? Would oil be phased out only to be replaced with biofuels and Brazil as the new fuel-exporting superpower? And what would happen without climate policies? Would energy trade naturally decline as oil and gas reserves are used up or would it continue to increase?
In our research we used a number of energy scenarios which depict:
- a world with an energy system which continues to develop in the same way it has developed over the last 50 years (i.e. business as usual)
- a world which implements ambitious policies to mitigate climate change and stabilize the climate at 2°C above pre-industrial levels (i.e. climate scenarios).
We looked at each type of world under a range of different policy choices: for example, phasing out nuclear energy or limiting the penetration of solar and wind energy, and including uncertainties such as different growth rates and fossil fuel availability over the long term.
We found that under a business as usual scenario global trade in oil, gas, and coal quadruples. Under a range of different climate-friendly scenarios, trade stabilizes at between half and twice the current level by 2030 and then falls throughout the rest of the century.
Falling trade would have significant implications for the interconnectedness of different world regions. In a business as usual scenario, the energy systems of all world regions remain interconnected, and becomes even more so. But under climate policies, regional energy systems diverge as each region gravitates to its own energy mix. This could decrease states’ investment in existing energy institutions and lead to a massive upheaval in the global energy governance landscape – thus rendering existing institutions obsolete.
Climate policies would affect not only the volume of energy trade but also how and where energy is exported and imported. Today, oil accounts for over 90% of transport demand and there are no real substitutes for fuel cars, trains and planes. Half of all countries in the world import more than 75% of their oil from only a few number of countries. That makes oil the most problematic fuel for energy security (for more on this see the Global Energy Assessment). Under the business-as-usual scenarios, these dynamics get worse over the next few decades.. However, under de-carbonization oil is phased out and no other fuel takes on similarly problematic dynamics.
It’s important to note though that over the short-term, climate policies could make oil even more of a problem: as cheap unconventional resources rise in price due to their carbon intensity, the geographical concentration of oil production would actually rise.
However, over the medium and long-term (three to four decades), climate action would make the energy system much more resilient compared to the business-as-usual case. Resilience, or the capacity for energy systems to respond to disruptions is just as important as avoiding risks such as decreasing energy dependence. Under climate scenarios, the diversity of energy options rises which means all our “energy eggs” would be distributed between different baskets. In addition, the energy system would become less sensitive to fluctuations in GDP, fossil resource assumptions, and energy intensity. This means that a low-carbon energy system would be less exposed to both price and supply shocks.
Reference
Jessica Jewell, Aleh Cherp, Keywan Riahi. (2014). Energy security under de-carbonization scenarios: An assessment framework and evaluation under different technology and policy choices. Energy Policy. Volume 65, February 2014, Pages 743–760 http://www.sciencedirect.com/science/article/pii/S0301421513010744
Aleh Cherp, Jessica Jewell, Vadim Vinichenko, Nico Bauer, Enrica De Cian. (2013). Global energy security under different climate policies, GDP growth rates and fossil resource availabilities. Climatic Change. November 2013. http://link.springer.com/article/10.1007%2Fs10584-013-0950-x
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.
Apr 9, 2014 | Energy & Climate, Science and Policy
By Matthias Jonas, IIASA, and Gregg Marland, Appalachian State University
Greenhouse gas emissions are seldom measured directly. They must be estimated from data such as on energy use and changes in land use. That means that estimates of greenhouse gas emissions from human sources are inherently uncertain.

Uncertainty around emissions may mean that reaching temperature targets would require greater cuts than previously thought. Central and Eastern Europe at night, taken from the NASA, International Space Station in 2011. Image Credit: NASA
In a new study with colleagues at IIASA and the Polish Academy of Sciences, we asked how uncertainty over time will affect short-term GHG emission commitments and long-term efforts to meet global temperature targets for 2050 and beyond. The new study addresses a fundamental problem: how to combine uncertainty about current and historic emissions (diagnostic uncertainty) with uncertainty about projected future emissions (prognostic uncertainty).
The paper introduces a concept we call the Emissions, Temperature, Uncertainty (ETU) framework.The ETU framework allows any country to understand its national and near-term mitigation and adaptation efforts in a more realistic context, where uncertainty is taken into account.
The ETU assumes that cumulative emissions can be constrained over time by international agreements that are binding, but that emissions can be estimated only imprecisely, and whether or not they will achieve an agreed temperature target is also uncertain. The ETU framework allows policymakers to understand diagnostic and prognostic uncertainty so that they can make more educated (precautionary) decisions for reducing emissions given an agreed future temperature target.
Diagnostic uncertainty refers to the uncertainty contained in current inventoried emission estimates and relates to the risk that true greenhouse gas emissions are greater than inventoried emission estimates. Prognostic uncertainty refers to cumulative emissions between a start year and a future target year and the global average temperature increase they would generate. It relates to the risk that an agreed temperature target is exceeded. In a nutshell, the ETU framework can be used to monitor a country’s performance – that is, past achievements as well as projected achievements – in complying with a future warming target in a quantified uncertainty-risk context.
While our study addresses whether or not the future increase in global temperature can be kept below 2, 3, or 4ºC targets, its primary aim is to use those targets to demonstrate the relevance of both diagnostic and prognostic uncertainty. The paper shows:
- Uncertainty is important in emissions: Both diagnostic and prognostic uncertainty need to be considered to facilitate better decisions on reducing emissions, given an agreed future temperature target.
- What these risks mean for emissions targets: We find, for example, that to nullify the diagnostic uncertainty-related risk, and to maintain a similar level of risk for exceeding a 2o target, the universally valid per-capita emissions target for 2050 resulting from the underlying cumulative emissions constraint needs to be shifted downward by nearly 10%.
- Risk and uncertainty are interdependent: This interdependence poses a challenge for decision-makers because they have to deal with uncertainty and risk simultaneously.
- Including land-use change is tricky: Determining cumulative emissions from land use and land-use change in this emission-temperature setting is difficult, because an achievable future state of sustainability for the terrestrial biosphere has not yet been defined.
Reference
Matthias Jonas, Gregg Marland, Volker Krey, Fabian Wagner, Zbigniew Nahorski (2014). Uncertainty in an emissions-constrained world. Climatic Change. April 2014. http://link.springer.com/article/10.1007/s10584-014-1103-6
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.
Mar 26, 2014 | Energy & Climate, Risk and resilience
By Reinhard Mechler, IIASA Risk, Policy, and Vulnerability Program
On March 25, member countries of the Intergovernmental Panel on Climate Change (IPCC) started discussing the key findings of the second volume of the Fifth Assessment Report (AR5) in Yokohama, Japan. The report focuses on climate-related impacts, risks and adaptation. Once approved by the 150+ governments present, together with IPCC’s other two parts of the report on physical climate science and mitigating greenhouse gases, it will constitute the scientific backbone for informing national and international climate policy over the coming years.

Flooded marketplace in Jakarta. Credit: Charles Wiriawan/Flickr (Creative Commons License)
A key aspect in climate adaptation is dealing with extreme events including natural disasters. It has become clear that extreme event risk constitutes a large part of the adaptation problem, particularly for developing countries and communities.
Despite this growing awareness, the international adaptation policy process is moving forward only slowly. Specifically, there is need for concrete advice for the Loss and Damage Mechanism, the main vehicle under the Climate Convention for dealing with climate-related impacts, which was agreed in Warsaw at the last Conference of the Parties in late 2013
In our commentary, published today in Nature Climate Change with colleagues from LSE, IVM and Deltares, we suggest that better understanding climate-related disaster risk and risk management can inform effective action on climate adaptation and point a way forward for policy and practice.
A key to moving forward is an actionable concept of risk. This involves identifying efficient and acceptable interventions based on recurrency of hazards—a concept known as risk layering. For example, for flood risk, this could mean identifying physical flood protection to deal with more frequent events, considering risk financing for infrequent disasters as well as relying on public and international compensation for extreme catastrophes. Risk layering overall points towards considering risk comprehensively as determined by climatic and non-climatic factors as well as considering portfolios of options that manage risks today and in the future.
The concept of risk layering underlies many areas of risk policy and management in agriculture, finance and insurance. It has been applied for disaster risks, mostly for insurance options, but not informed thinking on comprehensive risk management portfolios. Such broad understanding of risk management can also be helpful in identifying risks that are beyond adaptation–meriting international support, such as from the Green Climate Fund.
Climate risk management has now moved beyond theory. As one example, the megacity of Jakarta currently is setting up a multi-billion dollar program to manage increasing risk from sea level rise with large levees. This effort is integrated with a concern for managing flood risk and land subsidence, which are shaped by non-climatic factors, such as unplanned urbanization. The effort, therefore, involves options to implement acceptable building and zoning regulations for reducing exposure and vulnerability of houses and infrastructure to flooding.
Many policy-and implementation-specific questions remain. Over the coming months, IIASA researchers and our network will take the agenda on climate risk management forward with a focus on informing policy as well as providing actionable information on the ground.
Reference
Reinhard Mechler, Laurens M. Bouwer, Joanne Linnerooth-Bayer, Stefan Hochrainer-Stigler, Jeroen C. J. H. Aerts, Swenja Surminski & Keith Williges. 2014. Managing unnatural disaster risk from climate extremes. Nature Climate Change. March 26, 2014. http://www.nature.com/nclimate/journal/v4/n4/full/nclimate2137.html
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.
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