A review of trends and drivers of greenhouse gas emissions by sector from 1990 to 2018

Global greenhouse gas (GHG) emissions can be traced to five economic sectors: energy, industry, buildings, transport and AFOLU (agriculture, forestry and other land uses). In this topical review, we synthesise the literature to explain recent trends in global and regional emissions in each of these sectors. To contextualise our review, we present estimates of GHG emissions trends by sector from 1990 to 2018, describing the major sources of emissions growth, stability and decline across ten global regions. Overall, the literature and data emphasise that progress towards reducing GHG emissions has been limited. The prominent global pattern is a continuation of underlying drivers with few signs of emerging limits to demand, nor of a deep shift towards the delivery of low and zero carbon services across sectors. We observe a moderate decarbonisation of energy systems in Europe and North America, driven by fuel switching and the increasing penetration of renewables. By contrast, in rapidly industrialising regions, fossil-based energy systems have continuously expanded, only very recently slowing down in their growth. Strong demand for materials, floor area, energy services and travel have driven emissions growth in the industry, buildings and transport sectors, particularly in Eastern Asia, Southern Asia and South-East Asia. An expansion of agriculture into carbon-dense tropical forest areas has driven recent increases in AFOLU emissions in Latin America, South-East Asia and Africa. Identifying, understanding, and tackling the most persistent and climate-damaging trends across sectors is a fundamental concern for research and policy as humanity treads deeper into the Anthropocene

Allocating Ecological Footprints to Final Consumption Categories with Input-Output Analysis.

We present and discuss a method that allows the disaggregation of national Ecological Footprints by economic sector, detailed final demand category, sub-national area or socio-economic group. This is done by combining existing National Footprint Accounts with input–output analysis. Calculations in the empirical part are carried out by using supply and use tables for the United Kingdom, covering the reporting period 2000. Ecological Footprints are allocated to detailed household consumption activities following the COICOP classification system and to a detailed breakdown of capital investment. The method presented enables the calculation of comparable Ecological Footprints on all sub-national levels and for different socio-economic groups. The novelty of the approach lies in the use of input–output analysis to re-allocate existing Footprint accounts, in the detail of disaggregation by consumption category and in the expanded use of household expenditure data. This extends the potential for applications of the Ecological Footprint concept and helps to inform scenarios, policies and strategies on sustainable consumption. The method described in this paper can be applied to every country for which a National Footprint Account exists and where appropriate economic and environmental accounts are available. The approach helps to save time in data collection and improves the consistency between Ecological Footprint estimates for a particular human society from different researchers. For these reasons, the suggested methodology includes crucial steps on the way towards a standardisation of Ecological Footprint accounts

Carbon footprints of cities and other human settlements in the UK

A growing body of literature discusses the CO2 emissions of cities. Still, little is known about emission patterns across density gradients from remote rural places to highly urbanized areas, the drivers behind those emission patterns and the global emissions triggered by consumption in human settlements - referred to here as the carbon footprint. In this letter we use a hybrid method for estimating the carbon footprints of cities and other human settlements in the UK explicitly linking global supply chains to local consumption activities and associated lifestyles. This analysis comprises all areas in the UK, whether rural or urban. We compare our consumption-based results with extended territorial CO2 emission estimates and analyse the driving forces that determine the carbon footprint of human settlements in the UK. Our results show that 90% of the human settlements in the UK are net importers of CO2 emissions. Consumption-based CO2 emissions are much more homogeneous than extended territorial emissions. Both the highest and lowest carbon footprints can be found in urban areas, but the carbon footprint is consistently higher relative to extended territorial CO2 emissions in urban as opposed to rural settlement types. The impact of high or low density living remains limited; instead, carbon footprints can be comparatively high or low across density gradients depending on the location-specific socio-demographic, infrastructural and geographic characteristics of the area under consideration. We show that the carbon footprint of cities and other human settlements in the UK is mainly determined by socio-economic rather than geographic and infrastructural drivers at the spatial aggregation of our analysis. It increases with growing income, education and car ownership as well as decreasing household size. Income is not more important than most other socio-economic determinants of the carbon footprint. Possibly, the relationship between lifestyles and infrastructure only impacts carbon footprints significantly at higher spatial granularity

Input-output analysis and carbon footprinting: An overview of applications

This article provides an overview of how generalised multi-regional input-output models can be used for carbon footprint applications. We focus on the relevance and suitability of such evidence to inform decision making. Such an overview is currently missing. Drawing on UK results, we cover carbon footprint applications in seven areas: national emissions inventories and trade, emission drivers, economic sectors, supply chains, organisations, household consumption and lifestyles as well as sub-national emission inventories. The article highlights the multiple uses of generalised multi-regional input-output models for carbon footprinting and concludes by highlighting important avenues for future research. © 2009 The International Input-Output Association

The indirect CO2 emission implications of energy system pathways: Linking IO and TIMES models for the UK

Radical changes to the current national energy systems – including energy efficiency and the decarbonisation of electricity – will be required in order to meet challenging carbon emission reduction commitments. Technology explicit energy system optimisation models (ESOMs) are widely used to define and assess such low-carbon pathways, but these models only account for the emissions associated with energy combustion and either do not account for or do not correctly allocate emissions arising from infrastructure, manufacturing, construction and transport associated with energy technologies and fuels. This paper addresses this shortcoming, through a hybrid approach that estimates the upstream CO2 emissions across current and future energy technologies for the UK using a multi-regional environmentally extended input output model, and explicitly models the direct and indirect CO2 emissions of energy supply and infrastructure technologies within a national ESOM (the UK TIMES model). Results indicate the large significance of non-domestic indirect emissions, particularly coming from fossil fuel imports, and finds that the marginal abatement cost of mitigating all emissions associated with UK energy supply is roughly double that of mitigating only direct emissions

Mapping flows of embodied emissions in the global production system

Environmentally extended multiregional input-output (MRIO) analysis can be used to investigate final production and consumption attributions of emissions. As the distinction between the two attributions has been brought to the attention of policy-makers, there is an ever greater need to understand how and why they differ, by analyzing the connections between production and consumption activities. Seeking to meet this need, we present an approach for mapping flows of embodied emissions through a Leontief production system. The approach, seen as an extension of Structural Path Analysis (SPA), provides an exhaustive map of supply chain linkages between final production and consumption attributions of emissions. Whereas SPA is traditionally used to extract and rank individual supply chains according to the emissions occurring at the end of each chain, the mapping approach considers emissions embodied in the flows of intermediate products linking different economic sectors along supply chains. Illustrative results are presented from a global MRIO model and CO2 emissions for 2004. The emissions embodied in a sectors total output of products is also of interest: a method for calculating this is presented and shown to provide further insight into where in the production system a sectors overall emissions impact is concentrated

Estimating inter-regional trade flows in China:A sector-specific statistical model

China has huge differences among its regions in terms of socio-economic development, industrial structure, natural resource endowments, and technological advancement. These differences have created complicated linkages between regions in China. In this study, building upon gravity model and location quotient techniques, we develop a sector-specific model to estimate inter-provincial trade flows, which is the base for making a multi-regional input-output table. In the model, we distinguish sectors with less intra-sector input from those with larger intra-sector input, and assume that the former sectors tend to compete among regions while the latter tend to cooperate among regions. Then we apply this new method of inter-regional trade estimation to three sectors: food and tobacco, metal smelting and processing, and electrical equipment. The results show that selection of bandwidth has a significant impact on the assessment of inter-regional trade. Trade flows are more scattered with the increase of bandwidths. As a result, bandwidth reflects the spatial concentration of geographical activities, which should be distinguishable for different industries. We conclude that the sector-specific spatial model can increase the credibility of estimates of inter-regional trade flows