Can the U.S. achieve net-zero carbon emissions by 2050 without hurting the economy?

From last year’s floods in North Carolina to this year’s wildfires in Los Angeles, we are witnessing what happens in a world that has exceeded 1.5 degrees Celsius of warming above preindustrial times. Beyond that threshold, floods, droughts, wildfires and other climate impacts are expected to further escalate in frequency, intensity and lethality. To avert that scenario, nearly 200 signatory nations of the Paris Agreement on climate change have pledged to cap global warming at 1.5°C, a goal that will likely require all nations to collectively achieve net-zero carbon dioxide emissions by 2050. 

To scope out how the net-zero CO₂ emissions target can be met in the United States without imposing adverse effects on different economic sectors and income groups, nine researchers at the U.S. Environmental Protection Agency (EPA), MIT Center for Sustainability and Strategy (CS3), Colorado School of Mines, and RTI International—all participants in the 37th Energy Modeling Forum—have simulated several net-zero projections. Using a linked version of CS3’s U.S. Regional Energy Policy (USREP) model and the National Renewable Energy Laboratory’s Regional Energy Deployment System (ReEDS) model, they have produced a clearer picture of what a transition to net-zero might look like and the role played by different policies and technologies. 

Published in the journal Energy and Climate Change, the study’s key findings are:

• Reaching net-zero by 2050 via an emissions limit drives up the price of carbon to nearly 800 U.S. dollars per ton, requiring a significant deployment of direct air capture technology (DAC).
• The electricity sector reaches negative emissions (removing more CO₂ emissions than it produces) by 2050 primarily through biomass-fired electricity generation with carbon capture and storage (CCS).
• For the building and transportation sectors, electrification (using renewable energy to generate power) is the predominant means of decarbonization; for industrial sectors with limited electrification potential, carbon capture technology is the preferred option.
• Decarbonization is progressive (i.e., its economic burden increases with income level) due to the model’s emissions limit and assumption of lump-sum recycling of carbon permit revenues.
• When carbon capture technology improvement is accelerated, the effects are regressive (i.e., its economic burden decreases with income level), whereas technology improvement in other channels including DAC technology leads to more evenly distributed economic benefits.
• When the Inflation Reduction Act is included, the need for DAC is reduced, and industrial CCS investment occurs earlier and in greater amounts.

These findings show the roles of renewable energy, electrification, and negative emissions technologies in achieving net-zero CO₂ emissions in the U.S. by 2050 as well as the economy-wide implications of different net-zero pathways.

“Our results highlight the importance of considering interactions between technologies, policies and fiscal decisions when prescribing pathways that are economically viable for different sectors and equitable for different income groups,” says MIT CS3 Research Scientist Mei Yuan, a co-author of the study. “They also show that multiple pathways exist to achieve long-term climate goals, each presenting different tradeoffs in technology costs, emissions levels and equity.”