Modeling Vienna’s traffic: air pollution and health

By Anneke Brand, IIASA science communication intern 2016.

Accidents, lane closures, and congestion all affect the flow of road traffic and harmful emissions from vehicles. Live traffic data allow congestion to be detected more accurately and provide a more precise overview of vehicle emissions at different times and places. In his project for the Young Scientists Summer Program (YSSP), Fabian Heidegger investigates how road traffic affects air pollution in cities, using Vienna and surrounding areas as a case study.

Air pollution is a major problem in Europe and globally. Health impacts of air pollution include a range of respiratory and cardiovascular diseases. “10-20% of Europe’s urban population is exposed to excessive levels of nitrogen dioxide (NO2), along with several other air pollutants. NO2 pollution is highest along busy roads. Technical measures have so far often been circumvented, so cities are looking for other measures to reduce the pollution load. Traffic management has therefore gained interest as a way to reduce air pollution,” says Jens Borken-Kleefeld, Heidegger’s study leader at IIASA.

To calculate the amount of air pollution that cars and other vehicles release into the air, researchers use models that apply various sets of data: traffic networks, where and how far people drive, and emission factors of different vehicle categories. Input data for the model may include how many people live in a certain area, how many of them use cars, where they normally drive, and how many grams of pollutants (such as nitric oxide and NO2 gases) their type of cars emit per kilometer.

© Radub85 | Dreamstime.com

Inner city Vienna. © Radub85 | Dreamstime.com

Most of these models rely on average daily traffic data. For Heidegger’s YSSP project, which is related to his PhD work at the University of Natural Resources and Life Sciences  in Vienna, he is incorporating real-time data, measured every five minutes, into a traffic simulation model developed by Intelligent Transport Systems Vienna Region. A set of detectors in and around the city record the number and speed of vehicles. In addition, location data from the taxi fleet is incorporated into the traffic simulation. Heidegger can therefore immediately identify adverse traffic conditions like stop-and-go traffic, which has a high impact on emissions. This allows for a more accurate calculation and can help design traffic interventions for improving both traffic flow and air quality.

“In the case of a road closure, local emissions will obviously be lower at the specific road but total emissions for the area could be higher than before when drivers use alternative, longer routes or end up in stop-and-go traffic,” says Heidegger.

In order to understand how these diversions and the displacement of pollutants can affect overall emissions, Heidegger will first determine the emissions per street section, and second, what the effects are of diversions from day-to-day traffic patterns. Together with researchers from the Air Quality and Greenhouse Gases Program at IIASA, Heidegger plans to assess the impact of different intervention scenarios, for example an environmental zone in the city, where only modern cars will be allowed to enter. In a second scenario he will look at the effect of people commuting to Vienna, and a third scenario will explore the consequences of expanding pedestrian zones. The researchers hope that this study will better their understanding of the potential of traffic management to reduce air pollution.

 

More information

Air Pollution Policy Review 2011-2013

GAINS Model

AIR Program

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.

 

Making ends meet: Negative emissions for climate stabilization

By Sabine Fuss, Mercator Research Institute on Global Commons and Climate Change (MCC) and IIASA Ecosystems Services and Management Program

The Sleipner CCS plant in Norway was the world's first commercial CO2 storage facility. Photo: Kjetil Alsvik/Statoil

The Sleipner CCS plant in Norway was the world’s first commercial CO2 storage facility. Photo: Kjetil Alsvik/Statoil

Current strategies for limiting climate change to no more than 2°C above pre-industrial levels are centered around a shift towards less carbon-intensive technology, increases in energy efficiency, and changes in management and behavior.

This won’t be enough.

Global carbon dioxide concentrations have exceeded the benchmark of 400ppm, and it is clear that we’re headed for an overshoot. This means that to have a chance of stabilizing climate change below 2°C, we will actually need to extract greenhouse gases from the atmosphere, thus achieving what we call “negative emissions.” This is even more evident when we look at continued population growth, our dependence on existing infrastructure in the near future, and rising living standards in many emerging regions.

In a session on negative emissions at this year’s CFCC conference in Paris jointly organized by members of the Global Carbon Project at IIASA, MCC and CSIRO, and CO2-GEONET, a group of leading international researchers discussed the need for negative emissions and the implications of large-scale removal of CO2 from the atmosphere, and took a closer look at the outstanding questions and uncertainties on the topic.

Bioenergy with Carbon Capture and Storage (BECCS), and afforestation are two possibilities that could contribute to negative emissions, removing greenhouse gases from the atmosphere. © zlikovec |Dollar Photo Club

Bioenergy with Carbon Capture and Storage (BECCS), and afforestation are two possibilities that could contribute to negative emissions, removing greenhouse gases from the atmosphere. © zlikovec |Dollar Photo Club

A wide range of possibilities – but many open questions
The IPCC’s AR5 scenarios show that negative emissions could be achieved by combining carbon-neutral Bioenergy with Carbon dioxide Capture and Storage (BECCS), but also through afforestation. Most of the ambitious climate stabilization pathways show that we would need BECCS by the middle of the century, even though the removed emissions would not outweigh the remaining positive emissions at that point, that is, we would not yet see net negative emissions.

More precisely, the most recent scenarios of Integrated Assessment Models (IAMs) show that to achieve the 2°C limit, negative emissions of up to 13.2 GtCO2-eq./yr in 2100 are needed. This could be reached by BECCS, which might run into problems as competing for land with other demands, or a technology known as Direct Air Capture, which is more energy-intensive. Enhanced Weathering and afforestation might also deliver negative emissions, though of a smaller magnitude. However, all the presented negative emission technologies have their limits and none is a silver bullet. Clearly, there are more cards in the deck than just BECCS and we will have to aim for a portfolio respecting limits and trade-offs with other policy goals, but also opportunities and synergies.

One glaring clear point: negative emissions cannot be used to continue “business as usual” and then remove the bulk of the emissions mid-century. The required carbon flows would simply be too large. At the same time, such a high-emissions world would bring with it major environmental feedbacks, such as ocean acidification.  Thus, negative emissions have to be understood as just one element of a mitigation portfolio complementing drastic GHG emission reductions in the near term.

Many scenarios for limiting climate change require negative emissions by mid-century. Image: Global Carbon Project, 2014. http://www.globalcarbonproject.org/carbonbudget/

Many scenarios for limiting climate change require negative emissions by mid-century.
Image: Global Carbon Project, 2014.

While the large-scale use of biomass and its impacts have been at the center of bioenergy discussions for a while, CCS will also need to be scaled up to massive amounts of up to 25 GtCO2 per year by 2100. However, geology experts at the meeting were optimistic with respect to the storage potentials for these large amounts. The only challenge would be to find enough viable storage sites with assured capacity.

Other challenges include the need to investigate negative emission options that are not yet included in the AR5 scenarios, such as Enhanced Weathering, Direct Air Capture, and a method to improve CCS and BECCS with geothermal energy. How much the combined potential of these negative emissions options will indeed reduce temperatures also depends on the response of the climate system. However, two modelling teams presented new insights on reaction to overshoot, and negative emissions physically needed to keep global warming below 2°C.

While negative emissions are needed at large scale, many questions remain, which will need to be addressed very soon in order for scenarios meet reality. Communication must improve between scientists, politicians, practitioners, but also media and the public. Existing misunderstandings, for example, that negative emissions are just an excuse to continue on a business as usual pathway, or that negative emissions carry the same risks as geo-engineering, need to be resolved.

Read the full session report (PDF)

Sabine Fuss is leading the working group “Sustainable resource management and global change” at the Mercator Research Institute on Global Commons and Climate Change (MCC) in Berlin and holds a guest affiliation with IIASA’s ESM program. She is co-leading (with D. v. Vuuren) the research initiative “MAnaging Global Negative Emission Technologies (MaGNET)” hosted at the GCP Tsukuba Office

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.

Accounting for land use in EU climate policy

By Hannes Böttcher, Senior Researcher, Öko-Institut, previously in IIASA’s Ecosystem Services and Management Program

In or out?  Debit or credit? The role of the land use sector in the EU climate policy still needs to be defined

The EU has a target to reduce greenhouse gas emissions by at least 40% by 2030. This is an economy-wide target and therefore includes the land use sector, which includes land use, land use change and forestry. The EU is currently in the process of deciding how to integrate land use into this target. This is not an easy task, as we show in a new study.

© Souvenirpixels | Dreamstime.com

Land use includes activities, such as logging, that can release greenhouse gases into the atmosphere. But the sector also includes other processes that can remove greenhouse gases from the  atmosphere. Accounting for these processes is a complicated task. © Souvenirpixels | Dreamstime.com

The land use sector has several particularities that make it different from other sectors already included in the target, such as energy, industrial processes, waste, and agriculture. The most specific particularity is that the sector includes activities that cause emissions but also can lead to carbon being removed from that atmosphere, and taken up and stored in vegetation and soil. However, this removal is not permanent. Harvesting trees, and burning wood releases the carbon much more quickly than it was stored. Another particularity is that not all emissions and removals are directly caused by humans. This is especially true for removals from forest management.

In the past, the EU reported that uptake and storing of carbon through land use activities was higher than emissions from this sector. The European land use sector thus acted as a relatively stable net sink of emissions at around -300 to -350 Megatons (Mt) CO2 per year. But this might change in the near future: projections show the net sink declining to only 279 Mt CO2 in 2030.

Adding up carbon credits and debits
The emissions and removals that are actually occurring in the atmosphere are not exactly those that are currently accounted for under the Kyoto Protocol. Rather complicated rules exist that define what can be counted as credits and debits. Depending on how these rules develop, the EU sink may be accounted for to a large degree as a credit, or it could turn into a debit because the sink is getting smaller compared to the past. It is not likely that the entire sink will be turned into credits. Especially for the management of existing forests, which contributes a lot to the net sink, negotiators of the Kyoto Protocol have developed special accounting rules for the time before 2020. Under these rules, carbon credits only count if measured against a baseline.

The rules for the time after 2020 have not yet been agreed, however, as the Kyoto Protocol ends in 2020. In order to assess the impact of including the land use sector in the EU target in our new study, we had to make different assumptions, for example about how much wood we will harvest, the development of emissions and removals, and what the baseline for forest management should be. We then applied the existing Kyoto rules and alternative rules and assessed their impact on the level of ambition required to meet the EU’s target. It quickly became obvious: the assumptions we make and the rules we apply have very large implications for the 2030 Climate and Energy Framework.

One option of including land use discussed by the Commission is to take agriculture emissions out of the currently existing framework of the so-called ESD (an already existing mechanism to distribute mitigation efforts among EU Member States for specific sectors such as transport, buildings, waste and agriculture) and merge it with land use activities in a separate pillar. In our study we estimated the net credits that the land use sector could potentially generate, and found these credits could be as high as the entire emission reduction effort needed in agriculture. This would mean that in agriculture no reductions would be needed if the credits from land use were exchangeable between the sectors.

The impact on thannes-fighe target of 40% emissions reductions can be more than 4 percentage points if land use is included and the rules are not changed. This means that the original 40% target without land use would be reduced to an only 35% target. Other sectors would have to reduce their emissions less because land use seems to do part of the job. The target as a whole would thus become much less ambitious than it currently is. But this does not need to be the case. If accounting rules are changed in a way to account for the fact that the sink is getting smaller and smaller, land use would create debits. Including debits in the target would make it a 41% target instead and increase the overall level of ambition. This would be bad for the atmosphere because effectively emissions would not be reduced as much as needed.

It thus all depends on assumptions and rules. Before the rules are announced, the contribution of the land use sector cannot be quantified. Given this, we argue that the best option would be to keep land use separate from other sectors, give it separate target and design accounting rules that set incentives to increase the sink.

Reference
Böttcher H, Graichen J. 2015. Impacts on the EU 2030 climate target of inlcuding LULUCF in the climate and energy policy framework. Report prepared for Fern and IFOAM. Oeko-Institut.

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.

Uncertainty in an emissions-constrained world

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.

This image of Central and Eastern Europe at night was taken from the NASA, International Space Station in 2011. Image Credit: NASA

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.

REDD+: Cutting emissions, not trees, in the Congo Basin

By Aline Mosnier, IIASA Research Scholar

Aline Mosnier

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.

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.