How Can the U.S. Cut Emissions in Half by 2030?

In April 2021, the United States updated its Paris Agreement pledge to reduce economy-wide greenhouse gas (GHG) emissions 50-52 percent below 2005 levels by 2030. While the near-term goal is clear, there are still many questions about what actions to take, and how these various approaches may impact energy supply and demand, sector emissions pathways, and end-use consumers.

In a new collaborative article published in Science, I join researchers from the Natural Resources Defense Council, Bezos Earth Fund, University of Maryland Lawrence Berkeley National Laboratory, Pacific Northwest Laboratory, and the MIT Joint Program on the Science and Policy of Global Change to compare six different models (image below) to understand actions to achieve the 2030 GHG emissions reduction target. The research highlights common findings on “low-regret” strategies, which are relatively low-cost mitigation strategies under a range of potential future scenarios. These efforts include actions like significantly reducing coal generation, expanding wind and solar capacity, and supporting widespread adoption of electric transportation.

There are several robust findings from the research:

• Our models find that the bulk of emissions reductions come from electricity and transportation, which account for 69-89 percent of the 2030 reductions. While these sectors are the largest GHG contributors, it’s important to note that all sectors must be involved to achieve the 2030 target—electricity, transport, industry, buildings, as well as enhancing the carbon land sink and lowering non-carbon GHGs, such as methane from agriculture and fuels production.
• Immediate action is needed, as are additional policies. With current state policies and federal tax credits, carbon emissions will only decline by 6 to 28 percent from 2005 levels. This falls far short of the 50 percent emissions target. Additional wind and solar capacity must increase two to seven times their historical levels in the last decade to meet the 2030 target. Additionally, coal capacity retirements would need to exceed historic levels, leading to 90 to 100 percent reductions in coal generation by 2030.
• According to the six models, results indicate that the benefits of the 2030 target are broad and varied. In addition to GHG emissions reduction benefits of about $140 billion per year, achieving the 2030 target also can have significant and immediate benefits from air quality improvements. This transformation also has the potential to increase jobs, advance technology, and enhance international competitiveness. If approached thoughtfully, the energy transition can also advance equity and environmental justice—managing the distribution of burdens and benefits while building more affordable, reliable, and resilient systems.

In addition to the robust insights across the models, there are also several key differences in energy sector mitigation strategies. These differences include the level of electrification, share of electricity from renewables, and ratio of wind to solar builds. The comparison also shows variations in the extent of new natural gas capacity built to replace retiring coal capacity, balance renewables, and meet growing demand from electrification. Models also differ in their assessments of the role of emerging technologies, such as carbon capture and storage, and supporting infrastructure, such as transmission expansion.

You can learn more about our study by reading the article “Actions for Reducing U.S. Emissions at Least 50 Percent by 2030,” published in Science. We have also prepared a two-page research brief to highlight key findings. Plus, learn more about EPRI’s research to examine pathways and actions for reaching the U.S. 2030 target.