Deep Decarbonization of the World’s Energy Systems


The nations of the world have committed to decarbonization and 164 have submitted climate action goals (known as a Nationally Determined Contribution) to the United Nations. 

The NDC for the U.S. is a 26% to 28% reduction in greenhouse gas (GHG) emissions by 2025 from a 2005 baseline, with a commitment to aggressively push policies to achieve the higher level. The 2025 commitments are challenging under the best of circumstances and industrialized countries will need to considerably exceed such targets by mid-century if global temperature rise is to be held to two degrees Celsius. 

American leadership in this global effort is essential. The U.S. is currently on a trajectory to meet its interim target of a 17% reduction in GHG emissions by 2020 and emissions have declined in seven of the last ten years. These reductions are largely the result of increased energy efficiency and the reduced carbon intensity of the power sector.  Meeting the United States’ 2025 reductions is challenging but achievable through a combination of technologies, policies, regulations, incentives and investments.

There is a range of viable options for additional and significant emissions reductions from the electricity sector although these options, including nuclear power and CCUS for coal and natural gas generation, face major legal, regulatory, cost, market design, and investment impediments and hurdles. This is especially true in today’s political environment where the Trump Administration has rolled back or eliminated key policy levers, recommended major cuts in key R&D programs, clouded (at best) the future of U.S. participation in the Paris Agreement, Mission Innovation, and the Clean Energy Ministerial, and demurred on affirming its commitment to the G-7 energy security principles that include mitigating climate change, supporting energy R&D, and increasing energy efficiency. 

This suggests the need for an increased focus on analyzing the efficacy and interactions with state and regional policies, and policies with multiple benefits, as well as providing objective analysis and roadmaps for proponents of significant, accelerated actions to combat climate change.

While challenging, the electricity sector is arguably the easiest sector to decarbonize. Decarbonizing transportation, buildings and industry is more complicated and problematic as emissions sources are more distributed, varied and diffuse.  This makes end use emissions reductions at scale significantly more expensive on a per ton basis and relatively more difficult than for the power sector. Also, costs associated with certain end use emissions reductions, even if they are small, may be perceived as affecting the competitiveness of an industry, commodity or the overall economy. 

Electrification is a clear pathway for reducing emissions from each of these end use sectors but its efficacy is often overrated. The time pressures of climate change, and the costs and difficulties associated with emissions reductions from the industry, buildings and transportation sectors -- combined with concerns about competitiveness and the associated strength of political resistance -- point to the need for additional options to offset the emissions from these sectors as a key component of an effective climate strategy. This will include a specific focus on understanding negative carbon emissions and CO2 utilization, advancing the associated technology development and diffusion pathways, development of new business models, and identifying a range of investment options and policies to achieve emissions reductions at the Gt/year scale. 

In addition, some energy technologies that reduce GHG emissions, such as carbon capture, utilization and storage (CCUS), concentrated solar power, and geothermal generation, have the potential to increase energy’s water intensity; others, such as wind and photovoltaic solar power, can lower it. Dry cooling can reduce water intensity but may increase overall GHG emissions by decreasing generation efficiency. Though there can be a strong link between energy and water efficiency in energy technologies, many research, development, demonstration, and deployment funding criteria do not incorporate water-use or water performance metrics. Designing technologies and optimizing operations for improved water performance can have both energy and water benefits.

Finally, it should be noted that major environmental improvements can be made while growing the economy.  From 1970 to 2014, the U.S. population and GDP grew substantially; at the same time, pursuant to Clean Air Act requirements, aggregate emissions of criteria air pollutants from the electric power sector dropped 74 percent, even as electricity generation grew by 167 percent. Also, according to QER 1.2, the United States is the largest producer and consumer of environmental technologies. In 2015, the U.S. environmental technology and services industry employed 1.6 million people, had revenues of $320 billion, and exported goods and services worth $51 billion.

The global market for clean energy and environmental technologies is at the multi-trillion-dollar scale (some estimates of market size in developing countries alone put the value at $2.3 trillion). 

Even if the current Administration is not motivated by the disruptive threat of climate change, it should be cognizant of the fact that the United States will put itself at a substantial competitive disadvantage in the global clean energy marketplace if it does not participate in global climate change agreements and initiatives or make adequate investments in technology, policy and business model innovation.

Initial Analytical Projects for Deep Decarbonization of the World’s Energy Systems. 

EFI will write select white papers and meet with stakeholders to discuss and develop projects from several priority options: 

 EFI will identify opportunities for lowering the deployment barriers for low carbon technologies such as nuclear power (specifically including small modular reactors) and carbon capture, utilization and sequestration.

 EFI will analyze the effectiveness of state and regional policies, how they interact with other policies, and policies with multiple benefits, including benefits to mitigating climate change.

 EFI will analyze options and capacity for electrification of the transportation, space conditioning of buildings, and industrial processes.

 EFI will develop deep decarbonization strategies that address the interaction among environmental issues, such as GHG emission reductions and water management.

 EFI will assess the U.S. progress in meeting NDCs in 2021, closely tracking the recommendations and roadmaps of DOE’s Quadrennial Technology Review released in 2015.

 EFI will analyze the range of issues associated with large scale carbon management, and the associated technology development and deployment, as well as synergistic policy development and implementation strategies to affordably mitigate climate change.

 EFI will also analyze four large-scale carbon management options: 

  • Utilizing atmospheric carbon.
  • Recycling fossil-based carbon.
  • Sequestering fossil-based carbon.
  • Enhancing terrestrial sinks.           

This will entail analysis of, and support for, a significant basic research and development agenda and the ability to assess the most promising technology options for large-scale carbon management; associated systems analysis and modeling; the range and timeframes of diffusion pathways for key scalable technologies; supply chains; and the integration of technology options and policy pathways.  It will also entail a range of convening activities to gather broad expertise, insights, analysis and advice, as well as mobilizing support from a range of interested stakeholders. Large-scale carbon management options should be fertile ground for collaboration among Mission Innovation countries.