Lena Höglund-Isaksson

Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security

Why Wait? Tropospheric ozone can be dangerous to human health, can be harmful to vegetation, and is a major contributor to climate warming. Black carbon also has significant negative effects on health and air quality and causes warming of the atmosphere. Shindell et al. (p. 183) present results of an analysis of emissions, atmospheric processes, and impacts for each of these pollutants. Seven measures were identified that, if rapidly implemented, would significantly reduce global warming over the next 50 years, with the potential to prevent millions of deaths worldwide from outdoor air pollution. Furthermore, some crop yields could be improved by decreasing agricultural damage. Most of the measures thus appear to have economic benefits well above the cost of their implementation. Reducing anthropogenic emissions of methane and black carbon would have multiple climate and health benefits. Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at

EU Energy, Transport and GHG Emissions: Trends to 2050, Reference Scenario 2013

700 to

Sectoral marginal abatement cost curves: implications for mitigation pledges and air pollution co-benefits for Annex I countries

5000 per metric ton, which is well above typical marginal abatement costs (less than

Emission mitigation potentials and costs for non-CO2 greenhouse gases in Annex-I countries according to the GAINS model

250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide–reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.

Discrepancy between simulated and observed ethane and propane levels explained by underestimated fossil emissions

This report is an update and extension of the previous trend scenarios for development of energy systems taking account of transport and greenhouse gas (GHG) emissions developments. The purpose of this publication is to present the new European Union (EU) Reference scenario 2013. It focuses on energy, transport and climate dimensions of EU developments and the various interactions among policies, including specific sections on emission trends not related to energy. The Reference scenario was elaborated by a consortium led by the National Technical University of Athens (E3MLab) using the PRIMES model for energy and CO2 emission projections, the GAINS model for non-CO2 emission projections and the GLOBIOM-G4M models for LULUCF emission and removal projections. The scenarios are available for the EU and each of its 28 Member States simulating the energy balances and GHG emission trends for future years under current trends and policies as adopted in the Member States by spring 2012.

Mitigation Efforts Calculator (MEC): an online calculator for interactive comparison of mitigation efforts between UNFCCC annex 1 countries

Using the GAINS (Greenhouse Gas–Air Pollution Interactions and Synergies) model, we derived Annex I marginal abatement cost curves for the years 2020 and 2030 for three World Energy Outlook baseline scenarios (2007–2009) of the International Energy Agency. These cost curves are presented by country, by greenhouse gas and by sector. They are available for further inter-country comparisons in the GAINS Mitigation Efforts Calculator—a free online tool. We illustrate the influence of the baseline scenario on the shape of mitigation cost curves, and identify key low cost options as well as no-regret priority investment areas for the years 2010–2030. Finally, we show the co-effect of GHG mitigation on the emissions of local air pollutants and argue that these co-benefits offer strong local incentives for mitigation.

Air Quality-Carbon-Water Synergies and Trade-offs in China’s Natural Gas Industry

The GAINS model allows for estimation of costs and potentials for greenhouse gas (GHG) mitigation by individual GHGs. In this article, the GAINS model is used to assess mitigation potentials for non-CO2 GHGs in 2020 for all countries covered in the Annex-I of the Kyoto protocol. Mitigation measures for methane, nitrous oxide or fluorinated gases and their costs are identified and mitigation potentials and costs are compared with other available studies. Differences in the structure of economic sectors between countries are important determinants for the differences in the respective contribution of non-CO2 GHGs. For some countries, a successful application of mitigation options clearly hampers the potential still available for future reductions. While a number of options exist to reduce CO2 even at negative costs (∼25% of the overall reduction potential), this is not the case for non-CO2 gases. Non-CO2 gases, however, provide considerable potential in the very low cost range (less than 10 €/t CO2-eq), in particular as they are affected by options to abate CO2 as well. In the range for very cheap options, non-CO2 gases cover about 36% of the reduction potential, a fraction which is decreasing for the higher cost range, to about 26% for a carbon price of 100 €/t CO2-eq. These figures have been calculated for the total of Annex-I countries, assuming a social discount rate of 4%.

Cost-effective control of air quality and greenhouse gases in Europe: Modeling and policy applications

Ethane and propane are the most abundant non-methane hydrocarbons in the atmosphere. However, their emissions, atmospheric distribution, and trends in their atmospheric concentrations are insufficiently understood. Atmospheric model simulations using standard community emission inventories do not reproduce available measurements in the Northern Hemisphere. Here, we show that observations of pre-industrial and present-day ethane and propane can be reproduced in simulations with a detailed atmospheric chemistry transport model, provided that natural geologic emissions are taken into account and anthropogenic fossil fuel emissions are assumed to be two to three times higher than is indicated in current inventories. Accounting for these enhanced ethane and propane emissions results in simulated surface ozone concentrations that are 5–13% higher than previously assumed in some polluted regions in Asia. The improved correspondence with observed ethane and propane in model simulations with greater emissions suggests that the level of fossil (geologic + fossil fuel) methane emissions in current inventories may need re-evaluation.Observations of ethane and propane distributions in the atmosphere are reproduced in simulations with an atmospheric chemistry transport model, if fossil emissions are a factor of two to three higher than previously assumed.

Scenarios of global anthropogenic emissions of air pollutants and methane until 2030

The Mitigation Efforts Calculator (MEC) has been developed by the International Institute for Applied Systems Analysis (IIASA) as an online tool to compare greenhouse gas (GHG) mitigation proposals by various countries for the year 2020. In this paper, first we introduce the MEC conceptual model, i.e. the methodology and system architecture. Hereafter, the optimization process and its output results, namely cost curves are presented. We then discuss the abstract formulation of four different international greenhouse gas trading regimes that are conceivable. Finally, we illustrate the MEC as a tool for interactively evaluating complex cost curve information in the context of GHG mitigation targets as currently discussed in international climate policy circles.

The global methane budget 2000-2012

Both energy production and consumption can simultaneously affect regional air quality, local water stress and the global climate. Identifying the air quality–carbon–water interactions due to both energy sources and end-uses is important for capturing potential co-benefits while avoiding unintended consequences when designing sustainable energy transition pathways. Here, we examine the air quality–carbon–water interdependencies of China’s six major natural gas sources and three end-use gas-for-coal substitution strategies in 2020. We find that replacing coal with gas sources other than coal-based synthetic natural gas (SNG) generally offers national air quality–carbon–water co-benefits. However, SNG achieves air quality benefits while increasing carbon emissions and water demand, particularly in regions that already suffer from high per capita carbon emissions and severe water scarcity. Depending on end-uses, non-SNG gas-for-coal substitution results in enormous variations in air quality, carbon and water improvements, with notable air quality–carbon synergies but air quality–water trade-offs. This indicates that more attention is needed to determine in which end-uses natural gas should be deployed to achieve the desired environmental improvements. Assessing air quality–carbon–water impacts across local, regional and global administrative levels is crucial for designing and balancing the co-benefits of sustainable energy development and deployment policies at all scales.Focusing on China’s six natural gas sources and three end-use gas-forcoalsubstitution strategies in 2020, this study shows that, except for coal-based synthetic gas, replacement of coalwith gas usually has air–carbon–water co-benefits, although with air–water trade-offs in the magnitude ofimprovement.