Roadmap to 2050: A Manual for Nations to Decarbonize by Mid-Century

Executive Summary


The United Nations Intergovernmental Panel on Climate Change 2018 Report stated, “Limiting global warming to 1.5°C would require rapid, far-reaching and unprecedented changes in all aspects of society.” In recent years it has become clear that that scenario would require not only a transformation of our energy system in order to meet our global emissions targets, but also a rethinking of the way we control the temperature of our homes, travel around our planet, and manufacture our goods. Decarbonizing for a zero-emissions world by mid-century would require clear and efficient measures, adopted and implemented rapidly – and we have the technologies to pursue this direction.

Scientists, engineers, and technical experts will play a crucial role in the design of pathways for the decarbonization process of specific, energy-intensive sectors, notably power, heavy industry, transport, and buildings.

In April 2019, more than sixty technical experts from around the world gathered in Milan to attend a two-day Scientific Workshop hosted by Fondazione Eni Enrico Mattei (FEEM) and the Sustainable Development Solutions Network (SDSN) to discuss the state of decarbonization technologies that can accelerate the global shift towards decarbonization. The four main sectors identified for this exercise were power, industry, transport, and buildings. It should be noted that while land-use and agriculture were identified as critical additional sectors to close the emissions gap, analyses for these sectors are not included in this report.

Following the Paris Climate Agreement’s aim to strengthen the global response to the climate crisis “in the context of sustainable development and efforts to eradicate poverty,” the Roadmap to 2050 is conceived on a “systems approach,” aspiring to simultaneously address multiple objectives and promote policy instruments and technological solutions that can be used across sectors. The multiple objectives span decarbonization and environmental sustainability, economic prosperity (including poverty reduction), and social inclusion that leaves no one behind. Policy instruments include public investments, phase out of subsidies to fossil fuels, market mechanisms, regulatory framework and regulations on land use, while technological solutions address a wide range of current and emerging solutions, from smart power grids to synthetic fuels.

A systems perspective recognizes the interconnectivity of actions towards any one or more of these objectives, using any one or more of the mentioned policy instruments or technological solutions. An action in one can be detrimental to another, while some combined efforts could amplify their cumulative effects and achieve multiple objectives. For example, the power grid itself represents a complex system that must continue to operate reliably and efficiently even as it undertakes the deepest transformation in its history. No single policy or technology can achieve decarbonization by itself or be implemented without due consideration to its ripple effects, or to the delicate state of the current, broader system.

To use the proverbial expression, we must rebuild the airplane while it is in flight.

In taking a systems approach, many complementarities should be considered for managing the complexity of the energy system:

  1. Complementarities of variable renewable energy sources. Wind, solar, and hydropower vary by the minute, day, season, and year. Digital systems will play a large role in coordinating the augmented grid complexity and the required flexibility.
  2. Complementarities among zero-carbon technologies. As one obvious example, zero-emission vehicles depend on complementary zero-carbon energy sources and the infrastructure to fuel them.
  3. Complementarities of public and private investments. Parts of the energy system are in private, for-profit hands, and parts are publicly owned. It will take significant effort and analysis to harmonize public and private investments, to recognise the diverse role they can play and the synergies their joint action can create.
  4. Complementarities of natural and engineered systems. Achieving net negative emissions would require biological storage of carbon dioxide (CO2) in vegetation and soils via preservation of existing forests, restoration of degraded habitats, and reforestation to increase natural carbon sinks. Energy strategies that amplify land-use degradation must be ruled out.
  5. Complementarities of mitigation and adaptation. Adaptation measures can also contribute to mitigation strategies. Forest restoration and protection of coastal wetlands would help resist storm surges from rising sea levels, promote resilient food production, and secure carbon, thereby serving both adaptation and mitigation purposes.
  6. Complementarities of centralized and decentralized solutions. Renewable energy resources are by nature different from one place to another and restriction on land availability and use may require different power configurations.
  7. Complementarities of actions and strategies in different geographies. Efforts to address decarbonization might be similar for big cities in North America and in Europe, but they would not apply to sub-Saharan Africa. Urban areas are also different from rural areas where the fight to bring access to energy and other services to all is still a challenge. Trying to impose the same pathway in different contexts can lead to failure and to the continuation of business-as-usual scenarios.
  8. Complementarities of R&D activities supported by research institutions and academia, funded by public and private sectors. These activities should aims at promoting breakthrough innovation to feed continuously the process of decarbonization and keep under control any risk of lock-in to solutions that may fail to contribute to total decarbonization in the long run.

In order to make sense of this very complex and integrated system of energy and power, the authors of this report have identified Six Pillars of Decarbonization built on four general premises from which every country can begin to develop their roadmap to decarbonization by mid-century.


  1. The development of comprehensive climate policy will depend on specific geographical and social contexts, particularly in developing or low-income areas, in order to meet the needs of both society and the planet.
  2. Great cooperation and coordination in terms of policy design and implementation are required: stakeholders will need to consider the integrated use of different resources, technologies, or processes to guarantee inclusion and socioeconomic development of communities and enterprises’ competitiveness in the global market.
  3. Flexible and innovation-receptive regulatory frameworks are pivotal to address the challenge.
  4. Substantial efforts must be made to allocate consistent investments in research and development, as technological breakthroughs will trigger innovation and shorten the path toward global decarbonization.

Six Pillars

Zero-Carbon Electricity
A shift towards zero-carbon electricity mix.

Electrification of End Uses
The penetration of electricity, built on existing technologies, can enable a green conversion for the sectors currently using fossil-fuel energy.

Green Synthetic Fuels
Deployment of a wide range of potential synthetic fuels, including hydrogen, synthetic methane, synthetic methanol, and synthetic liquid hydrocarbons applicable for harder to abate sectors.

Smart Power Grids
Systems able to shift among multiple sources of power generation and various end uses to provide efficient, reliable and low-cost systems operations, despite the variability of renewable energy.

Materials Efficiency
Improved material choices and material flows, such as reduce, reuse, and recycle to significantly improve materials efficiency.

Sustainable Land-Use
Mainly involving the agriculture sector, as it contributes up to a quarter of all greenhouse gas emissions from deforestation, industrial fertilizers, livestock, and direct and indirect fossil- fuel uses.