Kate Scott

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.

Expression of both TNF-α receptor subtypes is essential for optimal skin tumour development

Keratinocyte-derived TNF-α acts as an endogenous tumour promoter and can also regulate AP-1 activity in mouse epidermis. To gain further insight into TNF-α signalling during skin tumour formation, mice deficient in TNFR1 (TNFR1−/− mice) or TNFR2 (TNFR2−/− mice) were subjected to chemical carcinogenesis. Tumour multiplicity was significantly reduced in TNFR1−/− and TNFR2−/− mice compared to wild-type (wt) mice, suggesting that both receptors have protumour activity. However, TNFR1−/− mice were markedly more resistant to tumour development than TNFR2−/− mice indicating that TNFR1 is the major mediator of TNF-α-induced tumour formation. TNFR1 and TNFR2 were both expressed in wt epidermis during tumour promotion and by primary keratinocytes in vitro. TPA-induced c-Jun expression was transient in TNFR1−/− and TNFR2−/− compared to wt epidermis and this was reflected by reduced induction of the AP-1-responsive genes granulocyte/macrophage-colony stimulating factor, matrix metalloproteinase-9 and matrix metalloproteinase-3. These genes were differentially regulated in TNFR1−/− compared to TNFR2−/− epidermis, suggesting that the TNF-α receptors act independently via different AP-1 complexes to transduce TNF-α signals during tumour promotion. In addition, TNFR2 cooperated with TNFR1 to optimise TNFR1-mediated TNF-α bioactivity on keratinocytes in vitro. Our data provide further insight into TNF-α signalling in malignancy and provide some rationale for the use of TNF-α antagonists in the treatment of cancer.

Application of Hybrid Life Cycle Approaches to Emerging Energy Technologies – The Case of Wind Power in the UK

Future energy technologies will be key for a successful reduction of man-made greenhouse gas emissions. With demand for electricity projected to increase significantly in the future, climate policy goals of limiting the effects of global atmospheric warming can only be achieved if power generation processes are profoundly decarbonized. Energy models, however, have ignored the fact that upstream emissions are associated with any energy technology. In this work we explore methodological options for hybrid life cycle assessment (hybrid LCA) to account for the indirect greenhouse gas (GHG) emissions of energy technologies using wind power generation in the UK as a case study. We develop and compare two different approaches using a multiregion input-output modeling framework - Input-Output-based Hybrid LCA and Integrated Hybrid LCA. The latter utilizes the full-sized Ecoinvent process database. We discuss significance and reliability of the results and suggest ways to improve the accuracy of the calculations. The comparison of hybrid LCA methodologies provides valuable insight into the availability and robustness of approaches for informing energy and environmental policy.

Consumption-based GHG emission accounting: a UK case study

Global GHG emissions continue to rise, with nearly a quarter of it due to trade that is not currently captured within global climate policy. In the context of current trade patterns and limited global cooperation on climate change, the feasibility of consumption-based emissions accounting to contribute to a more comprehensive (national) policy framework in the UK is investigated. Consumption-based emissions results for the UK from a range of models are presented, their technical robustness is assessed, and their potential application in national climate policy is examined using examples of policies designed to reduce carbon leakage and to address high levels of consumption. It is shown that there is a need to include consumption-based emissions as a complementary indicator to the current approach of measuring territorial emissions. Methods are shown to be robust enough to measure progress on climate change and develop and inform mitigation policy. Finally, some suggestions are made for future policy-oriented research in the area of consumption-based accounting that will facilitate its application to policy. Policy relevance Emissions embodied in trade are rapidly increasing and there is thus a growing gap between production emissions and the emissions associated with consumption. This is a growing concern due to the absence of a global cap and significant variation in country-level mitigation ambitions. Robust measurements of consumption-based emissions are possible and provide new insights into policy options. This includes trade-related policy (e.g. border carbon adjustments) and domestic policies (e.g. resource efficiency strategies). As climate policy targets deepen, there is a need for a broad range of policy options in addition to production and technological solutions. Consumption-based emissions are complementary to production-based emissions inventories, which are still the most accurate estimate for aggregated emissions at the global level. However, without consumption-based approaches, territorial emissions alone will not provide a complete picture of progress in regional and national emissions reduction.

TNF-α regulates epithelial expression of MMP-9 and integrin αvβ6 during tumour promotion. A role for TNF-α in keratinocyte migration?

Mice deficient in TNF-α (TNF-α−/− mice) are resistant to skin carcinogenesis and expression of MMP-9 is inhibited in TNF-α−/− mice during skin tumour development. In the early stages of tumour promotion, MMP-9 protein initially localized to the follicular epidermis but subsequently began to accumulate in the interfollicular epidermis of wild-type but not TNF-α−/− mice. Inhibition of TNF-α or MMP-9 function reduced keratinocyte migration in vitro. In addition, a deficiency of TNF-α delayed re-epithelialization in vivo and this correlated with reduced MMP-9 expression. Collectively, these data suggest that MMP-9 regulates keratinocyte migration in a TNF-α-dependent manner. Expression profiling of genes that control cell adhesion and migration revealed markedly lower levels of the integrin subunits αv and β6 in TNF-α−/− compared with wild-type keratinocytes in vitro. αvβ6 expression was upregulated by keratinocytes in vitro and during tumour promotion in vivo in a TNF-α-dependent manner. Furthermore, αvβ6 blockade significantly inhibited keratinocyte migration and TNF-α-stimulated MMP-9 expression in vitro. These data illustrate a novel TNF-α-dependent mechanism for the control of αvβ6 expression and suggest one pathway for TNF-α regulation of MMP-9. Increased MMP-9 and αvβ6 expression may stimulate epithelial cell migration during tumour formation and may be one mechanism whereby TNF-α acts as an endogenous tumour promoter.

A matrix metalloproteinase inhibitor which prevents fibroblast-mediated collagen lattice contraction

Matrix metalloproteinases (MMPs) and the specific tissue inhibitors of metalloproteinases (TIMPs) are involved in tissue turnover in normal and pathological processes including wound healing. Marimastat, a potent inhibitor of MMPs, was used to investigate the role of MMPs in an in vitro wound contraction model, the dermal equivalent, in which fibroblasts are grown in a collagen matrix. Marimastat inhibited fibroblast‐mediated lattice contraction and this inhibition was reversible upon removal of the inhibitor, indicating that MMPs play an important role in fibroblast‐mediated collagen lattice contraction, modelling what may happen when granulation tissue contracts in a healing wound.

Synthesis and Biological Evaluation of Coumarin-Based Inhibitors of NAD(P)H: Quinone Oxidoreductase-1 (NQO1)†

The synthesis is reported here of two novel series of inhibitors of human NAD(P)H quinone oxidoreductase-1 (NQO1), an enzyme overexpressed in several types of tumor cell. The first series comprises substituted symmetric dicoumarol analogues; the second series contains hybrid compounds where one 4-hydroxycoumarin system is replaced by a different aromatic moiety. Several compounds show equivalent or improved NQO1 inhibition over dicoumarol, both in the presence and in the absence of added protein. Further, correlation is demonstrated between the ability of these agents to inhibit NQO1 and computed binding affinity. We have solved the crystal structure of NQO1 complexed to a hybrid compound and find good agreement with the in silico model. For both MIA PaCa-2 pancreatic tumor cells and HCT116 colon cancer cells, dicoumarol shows the greatest toxicity of all compounds. Thus, we provide a computational, synthetic, and biological platform to generate competitive NQO1 inhibitors with superior pharmacological properties to dicoumarol. This will allow a more definitive study of NQO1 activity in cells, in particular, its drug activating/detoxifying properties and ability to modulate oncoprotein stability.

Indirect CO2 Emission Implications of Energy System Pathways: Linking IO and TIMES Models for the UK

Radical changes to current national energy systems-including energy efficiency and the decarbonization of electricity-will be required in order to meet challenging carbon emission reduction commitments. Technology explicit energy system optimization 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 multiregional 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 nondomestic 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 in 2050.

Global impacts of energy demand on the freshwater resources of nations

Significance Understanding the role of international trade in driving pressures on freshwater resources is key to meeting challenges at the water–energy nexus. A coupled trade and hydrological model is used to examine pressures on freshwater resources associated with energy production across the global economy. While the electric and gas sectors induce freshwater consumption predominantly within countries where demand originates (91% and 81%, respectively), the petroleum sector exhibits a high international footprint (56%). Critical geographic areas and economic sectors are identified, providing focus for resource-management actions to ensure energy and freshwater security. Our analysis demonstrates the importance of broadening the discourse on energy policy to address issues including freshwater scarcity, the role of international trade, and wider environmental and societal considerations. The growing geographic disconnect between consumption of goods, the extraction and processing of resources, and the environmental impacts associated with production activities makes it crucial to factor global trade into sustainability assessments. Using an empirically validated environmentally extended global trade model, we examine the relationship between two key resources underpinning economies and human well-being—energy and freshwater. A comparison of three energy sectors (petroleum, gas, and electricity) reveals that freshwater consumption associated with gas and electricity production is largely confined within the territorial boundaries where demand originates. This finding contrasts with petroleum, which exhibits a varying ratio of territorial to international freshwater consumption, depending on the origin of demand. For example, although the United States and China have similar demand associated with the petroleum sector, international freshwater consumption is three times higher for the former than the latter. Based on mapping patterns of freshwater consumption associated with energy sectors at subnational scales, our analysis also reveals concordance between pressure on freshwater resources associated with energy production and freshwater scarcity in a number of river basins globally. These energy-driven pressures on freshwater resources in areas distant from the origin of energy demand complicate the design of policy to ensure security of fresh water and energy supply. Although much of the debate around energy is focused on greenhouse gas emissions, our findings highlight the need to consider the full range of consequences of energy production when designing policy.

Extending European energy efficiency standards to include material use: an analysis

ABSTRACT Existing international emissions reduction policies are not sufficient to meet the internationally agreed objective of limiting average global temperature rise to ‘well below’ two degrees, resulting in an emissions gap. Materials – such as aluminium, cement, paper, plastics and steel – act as a carrier of industrial energy that allows, through trade, the transfer of embodied emissions between sectors and countries. However, the use of materials has been overshadowed by policies focusing on energy efficiency improvements and deployment of a low carbon energy supply. This article argues that policies based on material and product demand can support domestic climate change mitigation and reduce the emissions gap, yet there is little obvious integration between climate and material efficiency policies. The article investigates current ‘emissions flows’ through the EU economy and how much of these are captured and excluded from existing EU climate policies. We analyse the potential increase in emissions coverage that would be achieved by extending EU directives that currently target the energy use of products (cars, buildings and appliances) in operation, to include the emissions required to produce the goods (i.e. embodied emissions). The analysis shows that a greater integration of material efficiency strategies within climate change mitigation policy could significantly increase the emissions coverage of existing product policies. Key policy insights Consumption is a key driver of emissions and demand reduction is an important policy option in reducing emissions, at least in the short-term, to reduce the risks of a longer-term reliance on technology breakthroughs and while the EU carbon price remains low. Emissions embodied in material-intensive manufactured products consumed in the EU represent the equivalent of over 40% of EU production emissions, offering significant scope for emissions reductions along product supply chains. Consumption measures that target the use of materials and products offer complementary mitigation options to low carbon energy supply technologies alongside costs savings. Existing EU policies addressing the energy efficiency of products can be used to scale up material efficiency measures.