Committee on Climate Change

The Committee has developed a set of emissions reduction scenarios based on alternative assumptions about Government commitment to tackling climate change and policy effort.

Scenarios to meet the budgets to 2020

Our Extended Ambition scenario includes ambitious but reasonable assumptions on penetration of energy efficiency improvements and a number of measures which would cost more per tonne than our projected carbon price but which are important stepping stones on the path to 2050. It is broadly in line with policies to which the Government is committed at least in principle and includes:

• Significant progress towards low-carbon electricity generation 
• Insulation of most lofts and cavity walls in homes by 2015, and insulation of solid walls in 2 million homes by 2020 
• Significant penetration of renewable heat 
• 250 thousand electric cars and plug in hybrids by 2015, and 1.7 million by 2020, supported by appropriate charging infrastructure 
• Some behavioural change in homes and transport, e.g. with 4 million drivers trained in eco-driving by 2020 
• Emissions reductions from agriculture and waste in line with Government commitments.

The Extended Ambition scenario would be enough to meet the Intended budget for the non-traded sector without the need for offset credit purchase. Alongside the Interim budget for the traded sector (defined by the EU ETS cap), this would imply a 37% reduction in emissions by 2020 relative to 1990.

The Committee also developed a ‘Stretch Ambition’ scenario that adds further feasible abatement opportunities for which no policy commitment is in place, including additional penetration of energy efficient technologies and more significant lifestyle adjustments (e.g. further early replacement of old inefficient boilers in homes and road pricing).

Scenarios to meet budgets in the 2020s
 
The Committee developed a set of emissions reduction scenarios for the 2020s as part of the December 2010 report on the fourth budget. The Medium abatement scenario was recommended as an appropriate level of ambition to plan for to deliver the fourth budget and to prepare for deeper reductions to 2050. It forms the basis for our Domestic Action budget.

The Medium abatement scenario includes the following measures:

Power: Addition of 30-40GW (baseload-equivalent) low-carbon capacity to the system through the 2020s. This results in a reduction in carbon intensity from around 300 gCO₂/kWh in 2020 to around 50 gCO₂/kWh in 2030. The scenario includes a 30% demand increase from 2020 to 2030, reflecting increased uptake of electric vehicles and heat. The scenario could be delivered through a mix of technologies including renewable (e.g. wind, marine), coal and gas CCS, and nuclear – possible mixes are set out in our Renewable Energy Review. This scenario also includes investments in smart meters and increased interconnection with Europe to provide greater system flexibility, therefore addressing potential problems associated with intermittency. Read more about the power sector.

Buildings: Ongoing energy efficiency improvement through the 2020s, including insulation of 3.5m solid walls in the residential sector. The key option for supply-side decarbonisation in this scenario is heat pumps. These reach a penetration rate of 25% in the residential sector, and around 60% in the non-residential sector by 2030. There is a limited assumed role for district heating, reflecting uncertainties around technical and economic aspects of this option, with the possibility of deeper penetration as uncertainties are resolved. There is some use of biomass and biogas, although the majority of these energy sources is used in the industrial sector, given the lack of low-carbon alternatives for industry decarbonisation. Read more about buildings.
 
Industry: Use of biomass and biogas, which together account for around 25% of total heat demand by industry in 2030. There is a growing role for CCS in industry through the 2020s, which by 2030 reduces emissions by around 5 MtCO₂. Read more about industry.
 
Transport: Ongoing improvement of conventional vehicle efficiency, to 80 gCO₂/km for conventional cars and 120 gCO₂/km for conventional vans in 2030. There is 60% penetration of electric vehicles in new sales by 2030, the majority of which are assumed to be plug-in hybrids rather than pure electric, reflecting ongoing concerns around range constraints. There is a role for hydrogen vehicles in niche sectors (e.g. 50% of new buses in 2030 are hydrogen), with the possibility of broader penetration. We take a cautious approach to sustainable biofuels, with these remaining at levels recommended for 2020 in the Gallagher Review through the 2020s. Read more about surface transport.
 
Agriculture non-CO₂: Continuation of progress over the next decade implementing soils and livestock measures. The scenario recognises the possibility of, but does not require, consumer behaviour change, both as regards reducing waste and rebalancing diet to less carbon-intensive foods. It includes emissions reduction potential from increasing afforestation in the 2020s. The overall emissions reduction to 35 MtCO₂e in 2030 is low relative to abatement potential from all these measures, and could therefore be delivered in different ways. Read more about Non-CO₂ emissions and Agriculture.