Simulating the deep decarbonisation of residential heating for limiting global warming to 1.5C

Whole-economy scenarios for limiting global warming to 1.5C suggest that direct carbon emissions in the buildings sector should decrease to almost zero by 2050, but leave unanswered the question how this could be achieved by real-world policies. We take a modelling-based approach for simulating which policy measures could induce an almost-complete decarbonisation of residential heating, the by far largest source of direct emissions in residential buildings. Under which assumptions is it possible, and how long would it take? Policy effectiveness highly depends on behavioural decision- making by households, especially in a context of deep decarbonisation and rapid transformation. We therefore use the non-equilibrium bottom-up model FTT:Heat to simulate policies for a transition towards low-carbon heating in a context of inertia and bounded rationality, focusing on the uptake of heating technologies. Results indicate that the near-zero decarbonisation is achievable by 2050, but requires substantial policy efforts. Policy mixes are projected to be more effective and robust for driving the market of efficient low-carbon technologies, compared to the reliance on a carbon tax as the only policy instrument. In combination with subsidies for renewables, near-complete decarbonisation could be achieved with a residential carbon tax of 50-200Euro/tCO2. The policy-induced technology transition would increase average heating costs faced by households initially, but could also lead to cost reductions in most world regions in the medium term. Model projections illustrate the uncertainty that is attached to household behaviour for prematurely replacing heating systems

Faster LRAT Checking Than Solving with CaDiCaL

DRAT is the standard proof format used in the SAT Competition. It is easy to generate but checking proofs often takes even more time than solving the problem. An alternative is to use the LRAT proof system. While LRAT is easier and way more efficient to check, it is more complex to generate directly. Due to this complexity LRAT is not supported natively by any state-of-the-art SAT solver. Therefore Carneiro and Heule proposed the mixed proof format FRAT which still suffers from costly intermediate translation. We present an extension to the state-of-the-art solver CaDiCaL which is able to generate LRAT natively for all procedures implemented in CaDiCaL. We further present Lrat-Trim, a tool which not only trims and checks LRAT proofs in both ASCII and binary format but also produces clausal cores and has been tested thoroughly. Our experiments on recent competition benchmarks show that our approach reduces time of proof generation and certification substantially compared to competing approaches using intermediate DRAT or FRAT proofs

Net emission reductions from electric cars and heat pumps in 59 world regions over time

This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this record.Data availability: The data that support the findings of this study are available from the corresponding authors on reasonable request.Code availability: The computer code used to generate results that are reported in this study are available from the corresponding authors on reasonable request.Electrification of passenger road transport and household heating features prominently in current and planned policy frameworks to achieve greenhouse gas emissions reduction targets. However, since electricity generation involves using fossil fuels, it is not established where and when the replacement of fossil fuel-based technologies by1 electric cars and heat pumps can effectively reduce overall emissions. Could electrification policy backfire by promoting their diffusion before electricity is decarbonised? Here, we analyse current and future emissions trade-offs in 59 world regions with heterogeneous households, by combining forward-looking integrated assessment model simulations with bottom-up life-cycle assessment. We show that already under current carbon intensities of electricity generation, electric cars and heat pumps are less emission-intensive than fossil fuel-based alternatives in 53 world regions, representing 95% of global transport and heating demand. Even if future end19 use electrification is not matched by rapid power sector decarbonisation, it likely avoids emissions in world regions representing 94% of global demand.Engineering and Physical Sciences Research Council (EPSRC)Newton FundEuropean Research Council (ERC)European Union Horizon 2020European Commissio

Environmental impact assessment for climate change policy with the simulation-based integrated assessment model E3ME-FTT-GENIE

A high degree of consensus exists in the climate sciences over the role that human interference with the atmosphere is playing in changing the climate. Following the Paris Agreement, a similar consensus exists in the policy community over the urgency of policy solutions to the climate problem. The context for climate policy is thus moving from agenda setting, which has now been mostly established, to impact assessment, in which we identify policy pathways to implement the Paris Agreement. Most integrated assessment models currently used to address the economic and technical feasibility of avoiding climate change are based on engineering perspectives with a normative systems optimisation philosophy, suitable for agenda setting, but unsuitable to assess the socio-economic impacts of a realistic baskets of climate policies. Here, we introduce a fully descriptive, simulation-based integrated assessment model designed specifically to assess policies, formed by the combination of (1) a highly disaggregated macro-econometric simulation of the global economy based on time series regressions (E3ME), (2) a family of bottom-up evolutionary simulations of technology diffusion based on cross-sectional discrete choice models (FTT), and (3) a carbon cycle and atmosphere circulation model of intermediate complexity (GENIE-1). We use this combined model to create a detailed global and sectoral policy map and scenario that sets the economy on a pathway that achieves the goals of the Paris Agreement with >66% probability of not exceeding 2°C of global warming. We propose a blueprint for a new role for integrated assessment models in this upcoming policy assessment context.All authors acknowledge C-EERNG and Cambridge Econometrics for general academic and technical support. JFM, HP, PS, JV, NRE and PH acknowledge funding from the UK's research councils: JFM acknowledges funding from the Engineering and Physical Sciences Research Council (EPSRC), fellowship no. EP/K007254/1; JFM, PS and JV acknowledge funding from two Newton Fund grants, no EP/N002504/1 (EPSRC) and ES/N013174/1 (Economic and Social Research Council, ESRC). NRE and PH acknowledge funding from the Natural Environment Research Council (NERC) grant no NE/P015093/1. Additionally, PS acknowledges funding from Conicyt. JFM and HP acknowledge funding from The European Commission's Horizon 2020 Sim4Nexus grant, and from DG ENERGY, and AL acknowledges a postdoctoral fellowship from the University of Macau

START adolescents: study protocol of a randomised controlled trial to investigate the efficacy of a low-threshold group treatment programme in traumatised adolescent refugees

Introduction No evaluated therapeutic approaches, that can efficiently be established in routine mental healthcare, are currently available for traumatised adolescent refugees in Germany. This study evaluates the efficacy of the Stress-Traumasymptoms-Arousal-Regulation-Treatment (START) programme to reduce trauma-related symptoms and psychological distress in traumatised adolescent refugees based in Germany. Methods and analysis This randomised, waiting-list-controlled, multicentre trial with a 12-week follow-up will include 174 refugee minors with partial or full post-traumatic stress disorder who are fluent in either Arabic, Dari, English, German or Somali. Eligible refugee minors will be randomised to the START or waiting-list control groups. The manualised 8-week START programme is based on techniques of dialectical behaviour therapy (DBT), fosters adaptive coping with emotional distress and traumatic symptoms and comprises eight therapy modules and a booster session. Study assessments are planned at baseline, post-treatment (ie, after programme participation or waiting time), booster session at week 12 or 12-week waiting time, and at the 12-week follow-up. Primary and coprimary outcomes are changes in psychological distress and traumatic symptoms at post-treatment and will be analysed as response variables in linear mixed regression models. Secondary outcomes are changes in further trauma-related and other psychopathological symptoms, emotion regulation and intermediate effects of the programme at follow-up. We will also assess effects of the programme with ecological momentary assessments and on neuroendocrine stress parameters using hair cortisol. Ethics and dissemination This study has been approved by the lead ethics committee of Rhineland-Palatinate and the ethics committees of participating sites. The study results will be disseminated through peer-reviewed publications and scientific conferences

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Simulating the deep decarbonisation of residential heating for limiting global warming to 1.5 °C

Whole-economy scenarios for limiting global warming to 1.5 °C suggest that direct carbon emissions in the buildings sector should decrease to almost zero by 2050, but leave unanswered the question how this could be achieved by real-world policies. We simulate which policy measures could induce an almost complete decarbonisation of residential heating, the by far largest source of direct emissions in residential buildings. Under which assumptions is it possible, and how long would it take? We use the non-equilibrium bottom-up model FTT:Heat to simulate policies for a transition towards low-carbon heating in a context of inertia and bounded rationality, focusing on the uptake of heating systems. Our results indicate that the near-zero decarbonisation is achievable by 2050, but requires substantial policy efforts. We find that policy mixes are more effective for incentivising the uptake of fuel-efficient low-carbon technologies, compared to a residential carbon tax as the only policy. In combination with subsidies and procurement policies for renewables, near-complete decarbonisation could be achieved with a tax of 50–200 €/tCO2. Without being complimented by additional policies, carbon taxes show a decreasing marginal impact on total emission reductions, thus remaining insufficient for deep decarbonisation. In all scenarios, the decarbonisation of heating would increase projected heating costs faced by households initially, but could lead to cost reductions in most world regions in the medium term. We show that the potential impacts of policies highly depend on behavioural decision-making by households, especially in a context of deep decarbonisation and rapid transformation

Policy capacity for policy integration:Implications for the Sustainable Development Goals

LKYSPP Working Paper