Evolution of the United States Energy System and Related Emissions under Varying Social and Technological Development Paradigms: Plausible Scenarios for Use in Robust Decision Making

The
energy system is the primary source of air pollution. Thus,
evolution of the energy system into the future will affect society’s
ability to maintain air quality. Anticipating this evolution is difficult
because of inherent uncertainty in predicting future energy demand,
fuel use, and technology adoption. We apply scenario planning to address
this uncertainty, developing four very different visions of the future.
Stakeholder engagement suggested that technological progress and social
attitudes toward the environment are critical and uncertain factors
for determining future emissions. Combining transformative and static
assumptions about these factors yields a matrix of four scenarios
that encompass a wide range of outcomes. We implement these scenarios
in the U.S. Environmental Protection Agency MARKet ALlocation (MARKAL)
model. Results suggest that both shifting attitudes and technology
transformation may lead to emission reductions relative to the present,
even without additional policies. Emission caps, such as the Cross-State
Air-Pollution Rule, are most effective at protecting against future
emission increases. An important outcome of this work is the scenario-implementation
approach, which uses technology-specific discount rates to encourage
scenario-specific technology and fuel choices. End-use energy demands
are modified to approximate societal changes. This implementation
allows the model to respond to perturbations in manners consistent
with each scenario.