Feb 27, 2014 | Demography, Science and Policy
By Erich Striessnig, IIASA World Population Program
Is replacement level fertility really the best for society? Maybe not, say IIASA researchers. Photo Credit: Héctor Gómez Herrero via Flickr (Creative Commons License)
When asked what a desirable fertility level for populations might be, most politicians, journalists, and even social scientists would say it is around two children per woman, as this would – on the long run – prevent a population from either exploding or dying out. Other reasons for championing replacement level fertility include maintaining the size of the labor force and stabilizing the dependency ratio. But what is the evidence for this rule of thumb?
My colleague Wolfgang Lutz and I aimed to answer this question in a new study published in the journal Demographic Research. We found, not surprisingly, that the optimal fertility level strongly depends on what you mean by optimal.
The criteria for optimal fertility have often been motivated by nationalistic desires for larger and thus more powerful nations. Today our concerns run more towards the dangers of overpopulation for the environment, the climate, and the limited resources on Earth, dampening the enthusiasm for high fertility rates. But as fertility rates fall in many countries around the world, there is a growing concern about aging populations and an increasing number of elderly depending on an ever smaller number of people actively participating in the labor force.
While all of these fears relate to the same problem – an unbalanced population age-structure – the resulting assessments of what level of fertility would be desirable completely ignore the heterogeneity of the population with regard to important demographic characteristics, especially the population’s education structure.
In our study, we wanted to account for the fact that more education not only has higher economic costs, including later entry to the labor market and higher life expectancy, which can hardly been seen as a negative effect. But education also leads to higher productivity, less unemployment, and a healthier workforce that would on average retire later. To include these factors in our assessment, we ran thousands of simulations using varying constant rates of fertility.
What we found is that when we factor in education, the level of fertility that on the long run would lead to the lowest level of dependency is well below the supposedly magical level of two children per woman.
We also tried to link the effects of different fertility rates to the resulting environmental burden by factoring in expected carbon emissions. Not surprisingly, higher rates of fertility lead to faster population growth and more emissions. That suggests that an environmentally aware society should aim for even lower fertility levels.
While our research is not intended to prescribe fertility levels for individuals and countries, the conclusions drawn from this thought experiment suggest that the widespread popular notions that current fertility levels–for example in France or the US are just right because they are around replacement level, whereas they are too low in countries like Germany or Austria–may be wrong. According to our new study, the opposite is true.
Reference
Striessnig, E, Lutz W. (2014) How does education change the relationship between fertility and age-dependency under environmental constraints? A long-term simulation exercise Demographic Research, 30(16):465-492 http://www.demographic-research.org/volumes/vol30/16/
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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Dec 2, 2013 | Demography, Science and Policy
By Raya Muttarak, Research Scholar, IIASA World Population Program
For many years social scientists have observed a connection between economic downturns and a reduction in both unhealthy behaviors and mortality—a paradigm known as “healthy living in hard times.” One possible explanation for such counterintuitive findings was that people when people lose their jobs, have more spare time to dedicate to physical activities. Moreover, under an increased threat of unemployment, those who were still employed might limit their smoking and alcohol consumption in order to reduce their chances of being laid off. So the general agreement among social scientists has been that we should not worry too much about the impact of an economic crisis on health and mortality.
Our current global economic recession is the worst economic recession in contemporary history, however. And in a new study we found out that in fact, its consequences for health are very different from previous economic downturns. Since 2008, the number of smokers has increased substantially along with the increase in unemployed people.
In the new study, published in the journal Tobacco Control, we analyzed the effects of the current economic crisis on smoking in the United States, using data for around 2 million people from the Center for Disease Control’s Behavioral Risk Factor Surveillance System (BRFSS) survey for 2005 to 2010. In contrast to previous economic literature, we found an estimated increase of around 600,000 smokers due to the economic crisis.
Our study took into account the increase of the US population, the pre-crisis trends in smoking prevalence and the change in the distribution of population by socio-demographic characteristics.
We did find that “healthy living in hard times” still holds true for the employed individuals. Perhaps for fear of being laid off due to insurance reasons, these people maintain their healthy lifestyle. On the other hand, once without a job, people either started smoking or relapsed, possibly because of stress related to their new economic situation.
In contrast to previous economic literature, the new study finds an estimated increase of around 600,000 smokers due to the economic crisis. © Alexander Babich | Dreamstime.com
Since smoking prevalence by employment status remained more or less the same as before the crisis, a sharp increase in the number of unemployed individuals consequently led to a massive rise in the number of smokers. This has counterbalanced the trend in declining smoking rate among the employed.
Two main lessons can be drawn from our findings. First of all, YES…. this time it is different. The magnitude of the crisis has substantially changed the share of those with and without a job, with the latter being much more likely to engage in risky health behaviors. This in turns reversed most of the conclusions drawn by the previous literature. Second, we should not underestimate the impact of job-related stress factors on healthy behaviors. The idea that joblessness could be seen as a holiday where someone can engage in self-empowering activities is nice and reassuring, but it is meant to fail when unemployment is essentially unexpected and unwanted.
Reference
Gallus S, Ghislandi S, Muttarak R. Effects of the economic crisis on smoking prevalence and number of smokers in the USA. Tob Control. 2013 Aug 16. doi: 10.1136/tobaccocontrol-2012-050856. [Epub ahead of print] PubMed PMID: 23956058.
About the author
Raya Muttarak is a Research Scholar with the World Population (POP) Program. She came to IIASA in September 2011. Her current research covers three broad themes: 1) educational inequality and vulnerability and adaptation to climate change, 2) immigrant integration and ethnic inequality in education, the labor market and climate change adaptation, and 3) socioeconomic determinants of health risks and behaviors. More>>
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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Nov 14, 2013 | Environment, Science and Policy
By Aline Mosnier, IIASA Research Scholar
Aline Mosnier
Deforestation and forest degradation contribute substantially to greenhouse gas emissions, particularly in developing countries. The Reducing Emissions from Deforestation and Forest Degradation plus forest conservation, sustainable management of forests and enhancement of forest carbon stocks (REDD+) Initiative, launched in 2008 by the United National Framework Convention on Climate Change (UNFCCC), aims to help developing countries prevent such deforestation and degradation. It creates a mechanism that would provide financial compensation to developing countries that make efforts to address these problems. Some funding has started to flow to build REDD+ readiness plans and forest monitoring capacity. However, many methodological issues stand in the way of reaching agreements and attracting enough funding for the initiative to succeed.
One of the core ideas of REDD+ is that payments should be based on results. But particularly in Congo Basin countries, where I recently spent three weeks meeting with stakeholders and policymakers on REDD+ plans and goals, determining results is not an easy task.
How do we measure performance? First, we must agree on a benchmark to which the future efforts can be compared. The simplest benchmark is perhaps just to compare current efforts to the past: using past data has the advantage of being based on facts and consequently less prone to inflation. But for this to work, one has to believe that the past is the best predictor of the future.
The Congo Basin countries have a problem: they have high forest cover and low historical deforestation rates… but fast-growing needs.
Yaounde, Cameron. Photo credit: Aline Mosnier.
The low historical deforestation rates in the Congo Basin countries result from several factors. Some argue that conflicts, unfavorable investment climate, lack of infrastructure, and low levels of economic development have led to a “passive protection” of the forests. But the context is changing. Presidents of the Congo Basin countries have big plans–they want to become emerging countries within the next two decades–and they are looking for new opportunities. Foreign investment projects in mining, oil, agro-industrial plantations, and large-scale agriculture are now flourishing in the Congo Basin, and protected areas are under threat. Local communities could be threatened by expropriation and pollution from large scale projects, but at the same time these communities are also eager to see new employment opportunities.
What does this situation tell us about REDD for the Congo Basin? First, payments for living forests are necessary to avoid deforestation because this is the only way to convince developing countries that forests are valuable. These payments have to benefit both local communities who are living next to the forest, and governments who are making the decisions about large-scale conversion of forests.
Second, if payments are conditional to reduction compared to past deforestation, we can’t expect much from REDD in the Congo Basin countries. If payments are delivered based on lower future deforestation rates and are not underestimated compared to what could be foreseen according to countries development needs, the international community has a chance to make a change.
But this needs trust. Trying to quantify future emissions from deforestation and forest degradation is challenging and undoubtedly involves large uncertainties. However, by engaging with stakeholders to understand the local context while having independent funding, by building the models under the necessary scrutiny and scientific rigor, and by clearly communicating the results to the international community, scientists could play an important role in finding a fair deal to fight against future deforestation.
At IIASA, we are contributing to this objective under our REDD-PAC project by combining land use and systems analysis tools from IIASA, regional expertise of the National Institute for Space Research (INPE) in Brazil and the Central African Forest Commission (COMIFAC) in the Congo Basin, and the experience of UNEP-WCMC on the multiple benefits of REDD+.
Aline Mosnier contributed to work that will be presented at a special session organized by UNEP-WCMC and IIASA at the Global Landscapes Forum (GLF) at the COP 19th in Warsaw, highlighting the role of land use change models in supporting landscape-scale planning. She recently returned from travels through the Congo Basin, where she met with stakeholders and policymakers.
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Nov 7, 2013 | Energy & Climate, Science and Policy
Peter Lemke, head of the Climate Sciences Research Division at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany, is an expert on sea ice, a polar explorer, and the Chair of the IIASA Council. In this interview Lemke explains how climate change is affecting the Earth’s polar regions, and talks about a recent winter expedition to Antarctica.
On Monday, 11 November Lemke will give a public lecture on the topic at IIASA in Laxenburg.
Peter Lemke – Credit: Stephanie von Neuhoff (AWI)
How did you get interested in the cryosphere? What drew you to the poles?
When I was a young scientist, I was involved in climate modeling and especially the role of polar regions. For my PhD thesis I worked on sea ice extent data, trying to understand why we see changes.
That was in the late seventies, so it was not really climate change which was driving us, we just wanted to understand the climate system. Polar regions are an important part of the climate system. We tried to understand how they impact the other regions on the globe such as mid-latitudes and even the tropics.
When did you realize that climate change was affecting the polar regions?
Well the globe was already warming when I was starting my research in the mid-1970s. Sea ice was decreasing in extent, and ice was melting on the continents. Year by year, this trend became more significant. By the 1990s it was quite clear that there was a trend which was not just natural variation. The third IPCC report in 2001 just made it clear that man had an impact on the warming; at least a substantial part of it was due to increased greenhouse gases in our atmosphere.
A helicopter that was used to measure sea ice during Lemke’s 2013 Antarctic expedition. Credit: Peter Lemke (AWI)
What is happening now?
The changes we see now are even more dramatic than before, especially considering the Arctic sea ice. It hit a record low minimum in 2007 and we thought that this was the ultimate—as low as it would go. But then ice extent went even lower in 2012. While the ice extent this last summer was not quite so low, there is a strong trend in summer extent of sea ice. Our data indicate that it’s not just the extent but the thickness that’s changing. Measurements of sea ice thickness which our institute has performed over the last decade or so show a sharp thinning of the sea ice in the interior of the Arctic: The sea ice has thinned from an average of 2.5 to about 1 meter in only 10 years.
The other thing that is interesting is that the sea ice extent in the Antarctic is not decreasing at the same rate. On the contrary, it’s increasing in extent slightly. The question is of course is the ice mass also increasing, or is it just spreading out and thinning—like a dough that you roll out, getting wider but thinner?
How do you explain the growth in Antarctic sea ice, while Arctic sea ice is declining?
One explanation is that in the Southern Hemisphere the westerly winds are increasing, and through friction this drives the ice towards lower latitudes and the extent is getting a bit bigger. When the ice expands there is open water between ice floes, and it’s still cold enough in winter that ice freezes in the open patches.
There are other physical processes that may be involved, such as the heavy snow cover that blankets the Antarctic sea ice. Sometimes the heavy snow load submerges the ice floe underwater so that the interface of ice and snow is actually below sea level, and seawater drains into the snow and freezes. That may be one process, but there are others that are not really resolved yet.
We don’t yet have the answers to these questions, because there are very few measurements and you cannot deduce snow from satellite remote sensing data, yet. To find out, you have to go there and make measurements yourself. But winter expeditions are very rare. There are very few icebreakers that can actually go into the Antarctic winter into the sea ice. I have participated in four expeditions over the last 25 years: in 1989, 1992, 2006, and now 2013.
Working site during the 2013 Antarctic expedition. The wind chill was often between -50 and -60°C. Credit: Peter Lemke (AWI)
What did you find on your latest expedition?
Most of the data have yet to be analyzed. But from our early results, it looks like that the sea ice mass around Antarctica has increased slightly. Our measurements showed that the sea ice was more extensive, thicker and more densely packed as compared to our 1992 expedition, which was on the same track during the same season.
We have also observed a continuous warming in the deep ocean, which indicates that the warming trend that we see over the last couple decades is continuing. This indicates that the ocean has taken up a large fraction of the heat due to the increased greenhouse effect.
Why should people care what happens in the Arctic or in Antarctica?
Both polar regions are pristine regions not affected by humans as much as lower latitudes. Still you see the effects of mankind there. Once the sea ice is gone in the Arctic, we have lost an entire ecosystem which is adapted to the sea ice. Sea ice is a porous medium, and in the small cavities, there is rich life—tiny algae, crabs, krill—and this ecosystem supports an entire food chain up to the polar bear, whales, penguins that you find depending on which pole you are looking at.
Do you think that IIASA has a role to play in polar research?
IIASA is currently considering a new Arctic initiative, which could involve not just the climate system and the ecosystem but also the human system. Changes in the Arctic are already affecting people living at the coastlines. This coastline is made up of sand and ice, which is thawing. And as the sea ice is retreating, the coastline is now exposed to the increasing waves in the open ocean. Already now villages are already eaten up by the sea. At the same time, hunting grounds are changing for Inuit and other indigenous people who rely on sea ice for hunting. I think that’s something that IIASA can actually look at from a holistic view: human system, ecosystem, climate system.
What is one thing you want people to know?
Well often the poles, especially the Arctic, seem so far away that people don’t think that it is important for their lives. But if you have a polar storm coming from Svalbard, within two days it reaches the German coast, and within 10 days the entire Northern Hemisphere may be affected. The Arctic is only a few days away from us, and conditions that are changing in the Arctic will affect the climate conditions also in our region.
Emperor penguins spotted during Lemke’s 2013 Antarctic expedition. Credit: Peter Lemke (AWI)
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Oct 29, 2013 | Energy & Climate, Science and Policy
This post was originally published on the recharge.green blog. IIASA is a partner in the new project, which focuses on the potential for renewable energy in the Alps.
When I think of an alpine forest, I think of the towering cedar trees that blanket the Cascade mountains near my native Seattle, with trunks so broad you can’t reach your arms around them. I think of the shadowy quiet that envelops me as I wander through a mountain forest in my new home in Austria. I think of the scent of pine needles and the bounce of my feet on a trail softened by forest litter. The value of a mature forest to people like me who love the outdoors—its recreational value—is impossible to put into numbers.
We can, however, calculate the effects of different styles of forest management on more quantifiable criteria. We can determine how much carbon dioxide is taken up from the atmosphere and stored by long-growing forests. And we can estimate how much bioenergy we can sustainably produce by managing forests for biomass harvesting.
This is exactly what IIASA scientists have done for their first efforts in the recharge.green project. IIASA’s role in the project is to use our modeling expertise to explore the various possibilities for renewable energy expansion in the Alps. We are also looking at the tradeoffs and benefits of the different possible scenarios and ecosystem services (ESS). As a first step, researchers Florian Kraxner, Sylvain Leduc , Sabine Fuss (now with MCC Berlin), Nicklas Forsell, and Georg Kindermann used the IIASA BeWhere and Global Forest (G4M) models look at the tradeoffs between bioenergy production or carbon storage in alpine forests.
These graphs show the first results for recharge.green from IIASA’s BeWhere and G4M models, optimizing the location of bioenergy plants to maximize either carbon sequestration (top) or bioenergy production (bottom). The gradiant of green colors shows the amount of carbon storage over the landscape, while the red boxes (and according gradient in red) show the harvesting intensity in different harvesting areas.
“Managing forests optimally for bioenergy requires more intensive management,” says Kraxner. That means shorter rotations where trees are cut more often. Such a forest is made up of smaller trees that may look more like “close-to-nature plantations” than an old-growth forest. In contrast, managing forests for carbon storage means letting the trees grow older, also good for biodiversity and environmental preservation.
In their analysis, Kraxner and the team compared two management strategies: restricting bioenergy production to a small land area, and managing it intensively, or spreading bioenergy over a large land area but managing less intensively over the whole area. They found that the same amount of bioenergy could be produced by managing a small amount of land area intensively for bioenergy production. This more intensive management on a small area of land would free up a larger land area for preservation and protection or other special dedication to ecosystem services.
“Both methods are sustainable,” says Kraxner, “but the optics are different. Intensification can be a good solution to provide renewable energy and at the same time preserve biodiversity and the more intangible values of mature forests.”
What do you think? What should our priorities be in managing Alpine forests?
Oct 2, 2013 | Alumni, Energy & Climate, Science and Policy
By Anthony Patt, ETH Zurich and IIASA (From ETH-Klimablog)
The first of three working group reports of the Intergovernmental Panel on Climate Change (IPCC) was made public last Friday. Previous reports served as guidepost for climate policy development. And yet some policies were clearly more effective than others.
Over the next several months, the IPCC will release a series of three volumes, one from each of its three working groups, together constituting its Fifth Assessment Report (AR5). The Working Group (WG) 1 report, on the science of climate change, was just published, while reports from WGs 2 and 3, covering climate impacts and adaptation, and the challenge of reducing or stopping climate change, respectively, appear in March and April of 2014.
Established by the United Nations in 1988, the role of the IPCC is to assess the state of the science, communicating it in a manner that is useful to policy-makers. Three of the previous four assessment reports have come at critical times in climate policy development. The first two supported negotiations of the current global treaty and its first major revision. The Nobel Peace Prize winning Fourth Assessment Report (AR4) was released in 2007, intended to guide the negotiations to the successor to Kyoto.
The AR4 delivered a convincing two part message: that to avoid dangerous climate change the world must embark on a pathway completely eliminating greenhouse gas emissions from industry and land use change by the second half of this century, and that such a pathway is both technically and economically feasible. Many expected this message to lead to a successful negotiation process to be completed in Copenhagen in 2009.
International climate negotiations have made little progress, but the IPCC still has value, argues Patt.
But negotiators failed to reach an agreement in Copenhagen, and have made remarkably little progress in the four years since. Moreover, both the recently published AR5 WG1 report and early drafts of the WG2 report on climate impacts and adaptation suggest that their findings will strengthen those from AR4, but will not add anything dramatically new. Some say that the IPCC is no longer of any value. I disagree, for two reasons.
First, the most ambitious policy developments are now happening at the national level, with countries like Germany, Switzerland, and even the United States planning exactly the kind of transition away from fossil fuels and high emissions pathways that the AR4 suggested was both necessary and possible.1 There is reason to believe that the actions of this smaller number of countries will deliver the technological progress to make a global transition possible. Without the AR4, it is easy to imagine such countries having behaved differently, while the AR5 WGs 1 and 2 reports ought to provide added justification.
Second, deep differences of opinion have emerged concerning the best policies to achieve national decarbonization goals. Ten years ago, almost all analysts were convinced that carbon markets, i.e. trading in CO2 emissions certificates, represented the ideal policy instrument. But these have worked poorly, while portfolios of other instruments, including subsidies and regulations, have exceeded expectations. Researchers have studied these outcomes.e.g. 2 They have found, for example, that the more successful policy instruments are those that work to minimize the risks that investors in new technologies face.
The AR5 makes clear that an energy system transition remains necessary, and indeed now appears even more urgent than it did a few years ago. It is now possible for the IPCC, in its WG3 report, to provide a critical appraisal of alternative strategies. This is badly needed.
This post was originally published on the ETH Zurich Klimablog (in German).
1. Lilliestam, J. et al. An alternative to a global climate deal may be unfolding before our eyes. Clim. Dev. 4, 1–4 (2012).
2. Peters, M., Schneider, M., Griesshaber, T. & Hoffmann, V. H. The impact of technology-push and demand-pull policies on technical change – Does the locus of policies matter? Res. Policy 41, 1296–1308 (2012).
About the author
Anthony Patt is Professor at ETH Zurich, and a Guest Research Scholar in IIASA’s Program on Risk, Policy and Vulnerability, where he serves as head of the Decisions and Governance Research Group. His research is on the effectiveness of policies at addressing risks and uncertainties in the area of climate change, considering both the restructuring of energy systems and adapting to climate impacts and vulnerabilities. Read more>>
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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