Should Transportation Be Transitioned to Ethanol with Carbon Capture and Pipelines or Electricity? A Case Study

Energy, Health, and Climate Costs of Carbon-Capture and Direct-Air-Capture versus 100%-Wind-Water-Solar Climate Policies in 149 Countries

Air pollution, global warming, and energy insecurity are three major problems facing the world. This study first examines whether 149 countries can transition 100% of their business-as-usual (BAU) all-sector energy to electricity and heat obtained from 100% wind-water-solar (WWS) sources to solve these problems. WWS eliminates energy-related air pollution deaths and CO2-equivalent emissions while reducing end-use energy needs by ∼54.4%, annual energy costs by ∼59.6%, and annual social (energy plus health plus climate) costs by ∼91.8% among nations, giving energy- and social-cost payback times of 5.9 and 0.78 years, respectively. Conversely, "all-of-the-above" policies promoting carbon capture (CC) and/or synthetic (as opposed to natural) direct air carbon capture (SDACC) to reduce or offset CO2 emissions trigger, with full penetration of CC/SDACC across 149 countries, $60-80 trillion/y in social cost, or 9.1-12.1 times the WWS social cost and only 1.1-25.6% lower social cost than BAU. Even when all CO2 is stored, CC and SDACC increase air pollution, CO2-equivalent emissions (due to capture inefficiencies and not capturing non-CO2 greenhouse gases), energy needs, and equipment costs relative to WWS. Sensitivity tests reinforce this finding. Although full penetration is extreme, any CC/SDACC level increases social cost and emissions substantially versus WWS. Thus, policies promoting CC and SDACC should be abandoned.

Addressing Health Equity in the Context of Carbon Capture, Utilization, and Sequestration Technologies

PURPOSE OF REVIEW

To describe the role of health equity in the context of carbon capture, utilization, and sequestration (CCUS) technologies.

RECENT FINDINGS

CCUS technologies have the potential to both improve and worsen health equity. They could help reduce greenhouse gas emissions, a major contributor to climate change, but they could also have negative health impacts like air and noise pollution. More research is needed to fully understand the health equity implications of CCUS technologies. CCUS technologies have both health equity risks and benefits. Implementing misguided CCUS projects in vulnerable communities could exacerbate environmental injustice and health disparities and have the potential to increase carbon emissions. However, well-conceived projects could benefit communities through economic development. Governments, industry, and society should prioritize and expedite the reduction of CO2 emissions before considering carbon reductions via CCUS. Furthermore, CCUS projects must be thoroughly evaluated and should only proceed if they have demonstrated a net reduction in CO2 emissions and provide more benefits than risks to local communities. This underscores the importance of prioritizing health equity in the planning of CCUS projects.

Prioritizing Non-Carbon Dioxide Removal Mitigation Strategies Could Reduce the Negative Impacts Associated with Large-Scale Reliance on Negative Emissions

Carbon dioxide removal (CDR) is necessary for reaching net zero emissions, with studies showing potential deployment at multi-GtCO2 scale by 2050. However, excessive reliance on future CDR entails serious risks, including delayed emissions cuts, lock-in of fossil infrastructure, and threats to sustainability from increased resource competition. This study highlights an alternative pathway─prioritizing near-term non-CDR mitigation and minimizing CDR dependence. We impose a 1 GtCO2 limit on global novel CDR deployment by 2050, forcing aggressive early emissions reductions compared to 8-22 GtCO2 in higher CDR scenarios. Our results reveal that this low CDR pathway significantly decreases fossil fuel use, greenhouse gas (GHG) emissions, and air pollutants compared to higher CDR pathways. Driving rapid energy transitions eases pressures on land (including food cropland), water, and fertilizer resources required for energy and negative emissions. However, these sustainability gains come with higher mitigation costs from greater near-term low/zero-carbon technology deployment for decarbonization. Overall, this work provides strong evidence for maximizing non-CDR strategies such as renewables, electrification, carbon neutral/negative fuels, and efficiency now rather than betting on uncertain future CDR scaling. Ambitious near-term mitigation in this decade is essential to prevent lock-in and offer the best chance of successful deep decarbonization. Our constrained CDR scenario offers a robust pathway to achieving net zero emissions with limited sustainability impacts.