Improving access to modern energy can be achieved by using financial instruments to lower the cost of modern fuels and stoves, distribution programmes for improved biomass stoves, and ambitious electrification programmes, all targeted at the poorest households. In order to reduce greenhouse gas emissions it is necessary to improve energy efficiency and use more low or zero greenhouse gas emitting technologies. Standards and financial tools (e.g. taxation) can be effective policy instruments to unlock existing potential. Further electrification in the transport and household sectors could ensure more flexibility in reducing emissions. By 2050, around 60% of all energy would need to come from non-CO₂ emitting energy sources. Reducing non-CO₂ greenhouse gas emissions is also part of any effective strategy.

To implement these actions, five fundamental short-term policy priorities can be defined:

1. Substantially increase efforts to ensure modern energy for all

2. Start decarbonisation before 2020 and steadily accelerate afterwards

3. Prepare for adaptation

4. Ensuring sufficient financing

5. Make energy policies need to become more consistent

Access to modern energy sources improves human health mostly through better indoor air quality, as well as income opportunities through, for example, reductions in the time spent to collect firewood and . Electrification policies should target those communities that, from an economic perspective, would otherwise not be connected. Improving access to modern fuels for cooking and heating requires well-targeted subsidies on modern fuels, combined with policies that improve the affordability of the required stoves. Additional programmes include the distribution of improved biomass-fuelled cooking stoves for the poorest communities.

Even if access to modern fuels for cooking and heating would be achieved with fossil-fuel-based products, this would result in only a small increase in CO₂ emissions, (partly) compensated by reduced emissions from deforestation and of black carbon. The reasons why these increases would only be small are: 1) the per-capita energy consumption of the people involved would (initially) be low; 2) energy services would be provided much more efficiently; and 3) the emissions associated with the traditional use of biofuels would be reduced.

Scenario analyses show that emissions need to peak soon, in order for them not to overshoot the emission budget that is consistent with meeting the 2 °C climate target. Further delays could make climate policy very costly. In this context, government should consider phasing out the construction of coal power plants that do not use carbon capture and storage (CCS), before 2020. Early action may be achieved through appropriate pricing, but also through more direct government policies aimed towards utilities.

Important measures to reduce greenhouse gases are reducing non-energy-related greenhouse, energy efficiency improvements and low- and zero-carbon technologies. Although the potential for reducing non-energy-related greenhouse gases is limited, measures are very cost-effective and would have co-benefits related to air pollution. Furthermore, energy-efficiency improvements need to occur at double the historical rate. However, in the long run more reductions may be achieved through using low- and zero-carbon technologies, such as carbon-capture-and-storage, bio-energy, other renewables and nuclear power. Electrification and increased hydrogen use can help making the energy system more flexible.

This fundamental shift implies a strong reduction in the ratio between CO₂ emissions and GDP (decarbonisation). Historically, the highest improvement occurred during the 1980s, at around 2% annually, driven by the high energy prices and subsequent government response programmes. To achieve the 2 °C climate target, the decarbonisation rate would need to reach an annual level of around 4.5%, on average, over the 2010–2050 period. The required improvement rate is around three to four times the historical rate.

Energy efficiency has an important potential and may achieve multiple targets, simultaneously. Specific policy instruments, both financial and regulatory, may increase the likelihood of efficiency measures being implemented. Furthermore, on top of efficiency measures, also low-energy lifestyles would offer an interesting potential for change. Stimulation of dietary changes, an increased use of public transport and reduced use of heating and cooling all may be effective in reducing emissions.

The analysed energy transitions are expected to lead to a less than 2 °C increase in global mean temperature. However, uncertainties in the climate system imply that a warming by 3 °C or more may also be possible, even if emission reductions are successful, while there is also the risk of not achieving the emission targets. Therefore, countries will need to adapt to climate change and prepare for the impacts of a warming of 2 °C or more.

Estimates of the required level of investment in the energy system are likely to be several 1000 billion per year. Without the sustainability transition energy system investments towards 2050 are estimated the order of 4% of GDP. Meeting the sustainable development targets would lead investments in a different direction. Moreover, additional investments would be needed, certainly in the short term, estimated at around 1% to 2% of GDP; in particular, those to reduce greenhouse gas emissions. These investments can come from public and private sources. Often, private funding can be more effective. Ensure that public money is set aside for infrastructure and to provide access to modern energy for the poorest people. Well-designed subsidy schemes for clean fuels for poor customers have proven to be successful. However, once incomes reach the level on which households will have the ability to pay, these subsidies need to be phased out.

^a2010-2035; ^bsupply side only; ^cBased on current investments and increase in energy consumption; ^dclimate policy only; ^e2010-2030

Energy efficiency measures could contribute to multiple targets including those for climate, air pollution, and energy security. Removal of harmful subsidies is another example of areas from which multiple benefits could be obtained. In other cases, trade-offs between policy targets exist that have to be dealt with in a transparent way in relation to the long-term vision. Policy coherence would need to be discussed publicly and nationally. Furthermore, this would require a balance between 'private' and 'global public' aspects of the global energy system.