May 11, 2015 | Demography
IIASA demographer Erich Striessnig talks about new research linking population change with climate change scenarios.
What does your research say about population and climate?
In our recent review article published in the journal Population Studies, we give a summary of much of the work that has been carried out over the past few years both at IIASA and at the Wittgenstein Centre for Demography and Global Human Capital (IIASA, VID/ÖAW; WU) on the contribution of changes in population size and structures to greenhouse gas emissions, as well as societies’ capacity to adapt to climate change. Similar to Mia Landauer in last week’s blog entry, we emphasize the importance of addressing challenges to mitigation and adaptation jointly.
What’s new or unexpected in this study?
The main novelty behind our approach is the explicit inclusion of the full population detail by age, sex, and educational attainment in assessments of societies’ future adaptive and mitigation potential. This is exemplified in the context of IPCC-related climate change modelling which until recently has included only very limited information on the future of population. The new Shared Socioeconomic Pathways (SSPs), which were developed with a huge contribution by IIASA, are an important step to overcoming this situation and to make models of both future greenhouse gas emissions, as well as vulnerability and adaptive capacity with respect to climate change far more realistic.
Population characteristics – not just numbers – make a major impact on greenhouse gas emissions as well as people’s ability to adapt to a changing climate. ©Chris Ford via Flickr
Why is it important to consider the composition of population in regards to future climate change issues?
When thinking about the challenges of the future, it is important also to think about the capabilities that future societies will have to face them. I don’t mean that we should simply lean back and wait for science-fictional future technologies to solve all the problems of humanity, but a look at the changing future composition of populations around the world gives reason for optimism that future societies will be better at preparing, coping, and dealing with the consequences of yet unavoidable climate change than we are today.
What are the links between education and climate change?
Particularly in the developing world, education leads to reduced poverty. But economic growth and the resulting greater affluence, and consumption, also increases global CO2 emissions. So on a first look, education appears to worsen climate change. This has made some environmental activists skeptical about the value of education in the context of mitigation. But to avoid playing poverty eradication and well-being against climate change mitigation, it is necessary to look at behavioral differences at given levels of income. In fact, better education has been shown to be related to more eco-friendly consumption behavior, especially when it comes to home energy use and transportation, two of the main drivers of climate change. In addition to that, education has also been a major driver of technological advancements in the transition to cleaner energy sources.
Research shows that people’s education levels also play a role in how adaptable they are to potential climate-related impacts such as storms and floods. ©Aldrich Lim via Flickr
How do the new SSPs bring demography into the study of climate change?
Population growth is undoubtedly one of the main drivers of greenhouse gas emissions and thus climate change. What’s far less acknowledged is the importance of differential climate impact depending on demographic characteristics. Groundbreaking work by researchers from IIASA and the National Center for Atmospheric Research (NCAR) featured in the article has shown that people have different footprints when they are young than when they are old and that household consumption differs between rural and urban dwellers. Providing different scenarios for the future composition of populations by age, sex, and educational attainment, the new SSPs for the first time allow researchers from different fields to study the dynamics between population and climate change within a common reference frame.
References
Lutz W, Striessnig E (2015) Demographic aspects of climate change mitigation and adaptation. Population Studies: A Journal of Demography, 69(S1):S69-S76 (April 2015). doi: 10.1080/00324728.2014.969929
O’Neill, Brian C., Michael Dalton, Regina Fuchs, Leiwen Jiang, Shonali Pachauri, and Katarina Zigova. “Global Demographic Trends and Future Carbon Emissions.” Proceedings of the National Academy of Sciences 107 (October 2010): 17521–26. doi:10.1073/pnas.1004581107.
Note: This article gives the views of the interviewee, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.
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.
00
Dec 19, 2013 | Air Pollution, Demography, Environment
By Erich Striessnig, Research Assistant, IIASA World Population Program
We have all heard about the terrible air pollution in India’s cities. Average concentrations of particulate pollution exceed World Health Organization guidelines through most of India, most of the time. So why hasn’t anything been done? Is it really too expensive?
In a recent publication with fellow IIASA Population Program researcher Warren Sanderson and IIASA Mitigation of Air Pollution and Greenhouse Gases Program researchers Wolfgang Schöpp and Markus Amann, we set to find out. In the study, published in the journal Environmental Science and Technology, we showed that in fact, policy reforms in India targeted at reducing emissions of dangerous fine particulate matter could save thousands of lives, and at the same time save money.
Air pollution in India exceeds World Health Organization limits much of the time, which contributes to health problems and premature deaths. Photo Credit: Mark Danielson via Flickr (Creative Commons License)
Due to their very small size, small particles released by cars, factories, and other combustion can travel very deep down into people’s lungs and cause or worsen all sorts of health issues. In Indian cities, where concentrations of these pollutants are already quite high, the expected increase in economic output over the next two decades will be accompanied by an enormous increase in air pollution, leading to a higher number of sick days or even deaths.
Both of these effects could be prevented or at least reduced if stricter regulations on emission limits – already in place in other countries – were imposed. The new study shows that if India enacted pollution controls as stringent as according to European legislation, by the year 2030, the end of the study period, up to 2.5 million premature deaths would be prevented.
So how do pollution controls save money? Healthier people are more productive because they are sick less often. People who can expect to live longer in a cleaner environment are more likely to make investments which would again create jobs and boost the economy. Our study shows that by 2030 such investments would in fact more than pay for themselves, when the economic benefits of a healthier population are considered.
So why haven’t politicians started doing something already much earlier? One answer might be that such reforms initially only produce costs, whereas the benefits typically don’t crystallize before the next elections. Hopefully, this latest scientific evidence from a collaboration of IIASA population and air pollution researchers can offer these politicians an impetus to act. Read more on the IIASA Web site.
Reference Warren Sanderson, Erich Striessnig, Wolfgang Schoepp, and Markus Amann. 2013. Effects on Well-Being of Investing in Cleaner Air in India. Environmental Science and Technology. 47 (23), pp 13222–13229 DOI: 10.1021/es402867r
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.
00
You must be logged in to post a comment.