• Energy Research

The transport sector is growing fast in terms of energy use and accompanying greenhouse gas emissions. Integrated assessment models (IAMs) are used widely to analyze energy system transitions over a decadal time frame to help inform and evaluating international climate policy. As part of this, IAMs also explore pathways of decarbonizing the transport sector. This study quantifies the contribution of changes in activity growth, modal structure, energy intensity and fuel mix to the projected passenger transport carbon emission pathways. The Laspeyres index decomposition method is used to compare results across models and scenarios, and against historical transport trends. Broadly-speaking the models show similar trends, projecting continuous transport activity growth, reduced energy intensity and in some cases modal shift to carbon-intensive modes - similar to those observed historically in a business-as-usual scenario. In policy-induced mitigation scenarios further enhancements of energy efficiency and fuel switching is seen, showing a clear break with historical trends. Reduced activity growth and modal shift (towards less carbon-intensive modes) only have a limited contribution to emission reduction. Measures that could induce such changes could possibly complement the aggressive, technology switch required in the current scenarios to reach internationally agreed climate targets.

The transport sector is growing fast in terms of energy use and accompanying greenhouse gas emissions. Integrated assessment models (IAMs) are used widely to analyze energy system transitions over a decadal time frame to help inform and evaluating international climate policy. As part of this, IAMs also explore pathways of decarbonizing the transport sector. This study quantifies the contribution of changes in activity growth, modal structure, energy intensity and fuel mix to the projected passenger transport carbon emission pathways. The Laspeyres index decomposition method is used to compare results across models and scenarios, and against historical transport trends. Broadly-speaking the models show similar trends, projecting continuous transport activity growth, reduced energy intensity and in some cases modal shift to carbon-intensive modes - similar to those observed historically in a business-as-usual scenario. In policy-induced mitigation scenarios further enhancements of energy efficiency and fuel switching is seen, showing a clear break with historical trends. Reduced activity growth and modal shift (towards less carbon-intensive modes) only have a limited contribution to emission reduction. Measures that could induce such changes could possibly complement the aggressive, technology switch required in the current scenarios to reach internationally agreed climate targets.

Abstract Buildings are responsible for a major share of global final energy consumption and carbon dioxide (CO2) emissions. An analysis of the worldwide observed drivers of demand can highlight the policy actions most suited to drive the decarbonization of the building sector. To contribute to such an analysis, we carry out a mapping of the literature on determinants of energy demand and CO2 emissions from buildings. The work includes a list and classification of relevant studies in an on-line geographical map, a description of trends and gaps, and a narrative review. We identify 4080 articles in the Scopus and the Web of Science databases, of which 712 are relevant after screening at the title and abstract level, and 376 are included for data extraction. The literature base mostly addresses electricity and water use, in North America and Europe (57% of the literature) and Asia (27%). Econometric modeling approaches using panel data to calculate demand elasticities, dominate. These findings highlight gaps in terms of the studied variables (only 5% focus on CO2 emissions while a mere 1% have a lifecycle perspective), geographical scope (only 5% of the articles focus on Africa, 7% on Latin America and the Caribbean, and 5% on Oceania), and methodological approach (only 5% use qualitative methods). We confirm that worldwide, income, energy price and outdoor temperature are unequivocal drivers of buildings energy demand and CO2 emissions, followed by other indicators of scale such as population or heated floor area. Our analysis makes it clear that decoupling from rising wealth levels has not been observed. This will continue to challenge reductions in energy use and CO2 emissions from buildings in line with climate targets. Macroeconomic policies focusing on the impacts of income, energy price, population and growing floor area are needed in combination with technical policy to reduce the impact of outdoor climate.

Abstract Buildings are responsible for a major share of global final energy consumption and carbon dioxide (CO2) emissions. An analysis of the worldwide observed drivers of demand can highlight the policy actions most suited to drive the decarbonization of the building sector. To contribute to such an analysis, we carry out a mapping of the literature on determinants of energy demand and CO2 emissions from buildings. The work includes a list and classification of relevant studies in an on-line geographical map, a description of trends and gaps, and a narrative review. We identify 4080 articles in the Scopus and the Web of Science databases, of which 712 are relevant after screening at the title and abstract level, and 376 are included for data extraction. The literature base mostly addresses electricity and water use, in North America and Europe (57% of the literature) and Asia (27%). Econometric modeling approaches using panel data to calculate demand elasticities, dominate. These findings highlight gaps in terms of the studied variables (only 5% focus on CO2 emissions while a mere 1% have a lifecycle perspective), geographical scope (only 5% of the articles focus on Africa, 7% on Latin America and the Caribbean, and 5% on Oceania), and methodological approach (only 5% use qualitative methods). We confirm that worldwide, income, energy price and outdoor temperature are unequivocal drivers of buildings energy demand and CO2 emissions, followed by other indicators of scale such as population or heated floor area. Our analysis makes it clear that decoupling from rising wealth levels has not been observed. This will continue to challenge reductions in energy use and CO2 emissions from buildings in line with climate targets. Macroeconomic policies focusing on the impacts of income, energy price, population and growing floor area are needed in combination with technical policy to reduce the impact of outdoor climate.

AbstractA zero-carbon society requires dramatic change everywhere including in buildings, a large and politically sensitive sector. Technical possibilities exist but implementation is slow. Policies include many hard-to-evaluate regulations and may suffer from rebound mechanisms. We use dynamic econometric analysis of European macro data for the period 1990–2018 to systematically examine the importance of changes in energy prices and income on residential energy demand. We find a long-run price elasticity of −0.5. The total long-run income elasticity is around 0.9, but if we control for the increase in income that goes towards larger homes and other factors, the income elasticity is 0.2. These findings have practical implications for climate policy and the EU buildings and energy policy framework.

AbstractA zero-carbon society requires dramatic change everywhere including in buildings, a large and politically sensitive sector. Technical possibilities exist but implementation is slow. Policies include many hard-to-evaluate regulations and may suffer from rebound mechanisms. We use dynamic econometric analysis of European macro data for the period 1990–2018 to systematically examine the importance of changes in energy prices and income on residential energy demand. We find a long-run price elasticity of −0.5. The total long-run income elasticity is around 0.9, but if we control for the increase in income that goes towards larger homes and other factors, the income elasticity is 0.2. These findings have practical implications for climate policy and the EU buildings and energy policy framework.