Carbon model. Details are shown in Table 1.

Transcription

1 Carbon model The central carbon model used for constructing the ZCB scenario is a basic accountancy tool that takes output from other modelled areas (the Food and diets model, Land use model, Power Up and Power Down ), and measures them against a baseline year. For the ZCB scenario, our baseline year is We take the UK emissions accounts from this year, including international aviation and shipping [1, 2]. We first allocate those emissions that would be dealt with by other models. For example: Those directly associated with energy (energy generation, energy use, transport). Input from Power Up/Power Down for ZCB scenario. Those directly attributable to agricultural systems (aside from farm machinery, which is allocated under transport). Input from Food and diets model for ZCB scenario. Those directly attributable to land use, or change in land use. Input from Land Use model for ZCB scenario. For those emissions that are not taken into account in other models, then we find out to what extent the emissions can be reduced. Justifications are provided below. An additional impact on climate change due to the release of greenhouse gases by aviation as also added. This total is the figure that must finally become net zero. The other models are adjusted such that this constraint is met alongside all other internal constraints of those models. Details are shown in Table 1.

2 Table 1: Emissions accounts for ZCB scenario compared to 2010 baseline (Data from [1] and [2]) Sector Source Emissions (MtCO2e) Capture (MtCO2e) Net (MtCO2e) % ZCB Power Up/Power Down TOTAL Energy supply TOTAL Power Stations Refineries 16.5 Manufacture of solid fuels and other energy industries 18.5 Solid fuel transformation 0.2 Exploration, production and transport of oils 0.4 Offshore oil and gas - Flaring 4.2 Offshore oil and gas - Venting 0.6 Power stations - FGD 0.4 Exploration, production of gas 0.26 Coal mining and handling 1.43 Transport TOTAL Civil aviation (Domestic, Cruise) 1.3 Civil aviation (Domestic, Landing and take off) 0.5 Passenger cars 68 Light duty vehicles 15.2 Buses 4.7 HGVs 23.1 Mopeds & motorcycles 0.6 LPG emissions (all vehicles) 0.3 Other (road vehicle engines) 0.1 Railways 2.2 Railways - stationary combustion 0 Input from Power Up / Power Down

3 Buildings and industry Non-energy emissions Households, business and industry National navigation 2.4 Fishing vessels 0 Military Aircraft and shipping 3 Aircraft Support Vehicles 0.5 International aviation bunkers 31.8 International shipping bunkers 8.8 TOTAL Public Public 8.5 Business Iron and steel - combustion 12.7 Business Other industrial combustion 53.8 Business Miscellaneous industrial and commercial combustion 10.1 Business Energy recovery from waste fuels 0.4 Residential combustion 85.6 TOTAL TOTAL Energy Transport of gas Energy Disused Coal Mines Business Refrigeration and air conditioning 10.9 Business Foams 0.3 Business Firefighting 0.2 Gas leakage from NAEI [2] figures reduced by ratio of 2010 gas use (approx. 600 TWh) to ZCB 2030 use (approx. 100 TWh). Emissions from disused mines assume d to continue at 2010 level (figure from NAEI [2]). ***

4 Business Solvents 0.1 Business One Component Foams 0 Business Residential Electronics, electrical insulation and sporting goods Use of non aerosol consumer products Emissions from various consumer products including house and garden machinery [2]. Assume reduced to zero by switching to zero carbon fuels or product substitution or elimination. Residential Accidental vehicle fires 0 Remains as 2007 negligible. Residential Aerosols and metered dose inhalers 2.7 Industrial Processes Sinter production 1.2 see 'Total Iron and Steel' Cement production 3.8 AEA [3] identify 4.4 MtCO2 from 9.6 MtCO2 (54% reduction) without CCS but this includes energy emissions. 40% clinker substitution is considered feasible [3]; we use a 40% process CO2 emission reduction from 2007 levels. ZCB would also have switch to alternative materials for buildings etc. but may also require cement for energy infrastructure, hence assume 2007 levels of cement production. Lime production 0.2 Non-cement lime production - assumed to remain at 2007 levels. Limestone and dolomite use 0.8 Iron and steel related emissions reduced as part of Total Iron and Steel. Emissions associated with power station flue gas

5 desulphurization assumed to reduce to zero because of elimination of coal power stations and drastic reduction of use of gas power stations. Soda ash production and use 0.2 Remains as 2007 Fletton bricks 0.1 Remains as 2007 Ammonia production 1 Use hydrogen from electrolysis, therefore, emissions are reduced to zero. Total iron and steel AEA [3] states potential for abatement of of MtCO2e by This is maximum feasible abatement and appears to be achievable by several routes, therefore assume it represents full abatement of non-process emissions by fuel switching and some reduction of process emissions by more recycling. Iron and steel 1.5 see Total Iron and Steel. Aluminium production 0.4 Emissions from ore reduction remain the same as For F-gases 75% should be achievable for ZCB as per [11] and is applied to Nitric acid production 1.3 By changing production processes, it is possible to reduce emissions from the production of these acids by 90 98% at a low cost [11]. 97% reduction from 2007 level assumed for ZCB. Adipic acid production 0 By changing production processes, it is possible to reduce emissions from the production of these acids by 90 98% at a low cost [11]. 97% reduction from 2007 level assumed for ZCB. Other - Chemical industry 0.1 Remains as 2007 Halocarbon production 0.1 Magnesium cover gas 0.1 Settlements Settlements remaining settlements Remains as 2010

6 Biomass burning 0.1 Remains as 2010 Land converted to settlements 3.6 Tends to zero as no further urbanisation Waste management TOTAL [9] states 91% reduction on 1990 levels by 2020 Methane emissions used for energy (see Land Landfill 14.7 Use ) [9], N2O emissions reduced by 25% through enclosing the tanks and installing waste gas scrubbing. [10] Waste-water handling 1.5 Methane emissions from wastewater processing used to produce energy (see 'Land Use') [9], and N2O emissions reduced by 25% [10] Waste Incineration 0.3 Remains as 2010 Land use TOTAL Agriculture, food and diets TOTAL Agriculture Stationary and mobile combustion 4.6 Enteric Fermentation Breakdown of pesticides 0 Cattle 11.9 Sheep 3.1 Goats 0 Horses 0.1 Pigs 0.1 Deer 0 Wastes Cattle 1.8 Sheep 0.1 Goats 0 Horses 0 Pigs 0.5 Poultry 0.3 Deer 0 Manure liquid systems 0.1 Manure solid storage and dry lot 1.2 Other manure management (N2O) 0.5 Input from 'Food and Diets'

7 Other Direct Soil Emission 26.4 Field burning of agricultural wastes 0 Cropland Biomass burning Liming 0.5 Cropland remaining cropland 5.4 Land converted to cropland 6.2 N2O emissions from disturbance associated with land-use conversion 0.6 to cropland Carbon capture TOTAL Forest Land Forest Land remaining Forest Land Forest Land Biomass burning Forest Land Land converted to forest land Forest Land Direct N2O emission from N fertilisation of forest land 0 Grassland Liming Grassland Biomass burning Grassland Grassland remaining grassland Grassland Land converted to grassland Input from 'Land Use' Wetlands Wetlands remaining Wetland Non-CO2 emissions from drainage of soils and wetlands 0 Other Harvested wood Crown Dependencies Additional carboncapture * Biochar Silo storage Total (without aviation and shipping) Total emissions 628.3

8 Aviation impact ** Proportion of aviation remaining in the scenario multiplied by 2010 value. Total impact This value that must total zero. * These two do not appear in UK carbon accounts but form part of carbon capture in the ZCB scenario. ** Emissions Weighting Factor (EWF) for aviation (akin to GWP for GHGs) = 1.6 [8] Note that this figure is highly debated. [4, 5, 6, 7] *** A 2007 baseline is used for industry non-energy emissions. This is in line with assuming that industrial output remains at 2007 levels.

9 References [1] DECC (2013) Official statistics: Final UK greenhouse gas emissions, 5 February Department of Energy and Climate Change. final-uk-emissions-estimates [2] DEFRA (2013) National Atmospheric Emissions Inventory: UK emissions data selector. Department for Environment, Farming and Rural Affairs. [3] AEA (2010) Analysing the Opportunities for Abatement in Major Emitting Industrial Sectors, 8 th December AEA. [4] [5] Department for Transport (2010). DfT Aviation Environment and Atmospheric Expert Technical Support - [6] [7] Discussion between RFI and EWF CO2_effects_of_aviation_in_emission_trading_schemes [8] Inclusion of non-gas RF in RFI (and so to use EWF) [9] AEA Technology Environment (1998) Options to reduce methane emissions (Final Report), A report produced for DGXI, November. AEA Technology Environment. [PDF] eu/environment/enveco/climate_change/pdf/methane_emissions.pdf [10] AEA Technology Environment (1998b) Options to Reduce Nitrous Oxide Emissions (Final Report), A report produced for DGXI, November. AEA Technology Environment. [PDF] [11] Lucas, P. et al. (2007) Long-term reduction potential of non-co2 greenhouse gases. Environmental Science & Policy, 10(2), pp