Decarbonisation of the global energy system is one of the big challenges society faces today. The Paris Agreement, adopted in 2015, states that efforts should be pursued to limit the temperature increase to 1.5°C above pre-industrial levels. This is a tightening of earlier agreements that put the limit at 2°C.
What Does Such Increased Ambition Mean for the Global Energy System?
The temperature effect of CO2 emissions is not primarily determined by the level of emissions in a future year; rather, it is by the cumulative amount of emissions, or the carbon budget. To stay within the carbon budget, emissions need to be reduced—and fast. If we keep on emitting CO2 at the current pace, the carbon budget to limit the temperature increase to 1.5°C will be exceeded in one or two decades.
What Could a Fast Energy Transformation Look Like?
Population and GDP growth results in an increasing demand for energy services like space heating and cooling, transportation, and materials production. There are several critical levers to constrain emissions against the background of these developments:
- Ongoing efforts to deliver all energy services in an efficient way
- Electrifying energy consumption, especially for buildings and transportation
- Fast penetration of wind and solar in the electricity sector
- Adopting a range of other renewable energy technologies, from solar heat to electricity-based hydrogen
- Bioenergy as a fuel source for the manufacturing industry and specific transportation needs and a role for carbon capture and storage (CCS) in specific sectors
By giving preference to options that have high social and political acceptability, Ecofys, a Navigant company, developed a decarbonisation scenario where maximum feasibility is achieved. With strong energy efficiency improvement, this decarbonisation scenario shows it is possible to bring global energy use below current levels to 435 EJ, which is a strong contrast to business as usual growth to about 800 EJ. However, while the total primary energy supply in the scenario is reducing slightly, electricity demand is expected to almost triple. We estimate that all this energy can be supplied from zero-carbon or low carbon energy sources because of the unprecedented scale up of technologies such as solar PV, wind turbines, EVs, and heat pumps.
(Source: Ecofys, a Navigant company)
Despite the global energy system’s rapid reduction of CO2 emissions in our disruptive decarbonisation scenario, cumulative CO2 emissions beyond 2014 are calculated to be 680 billion tonnes, likely exceeding the carbon budget. However, combined with options such as afforestation and agricultural carbon sequestration, it seems possible to stay within a carbon budget compatible with a maximum temperature increase of 1.5°C.
Fast Global Action Is Needed
Fast global action is needed, and the way we live, produce, consume, and dispose of products and services needs to be redesigned to reduce dependence on future negative emissions. An energy system transformation as set out in a recent report by Ecofys, a Navigant company, Energy transition within 1.5°C, is feasible but highly disruptive because it is based on technologies that are already available. Nevertheless, it will influence all players in the energy system due to strong electrification and the increased use of bioenergy. Existing businesses will need to be completely reoriented and new business lines developed to cope with the energy technology requirements of the future.