  The planned US withdrawal from the Paris Agreement as well as uncertainty
about federal climate policy have raised questions about the country's future
emissions trajectory. Our model-based analysis accounts for uncertainty in fuel
prices and energy technology capital costs and suggests that market forces are
likely to keep US energy-related greenhouse gas emissions relatively flat or
produce modest reductions: in the absence of new federal policy, 2040
greenhouse gas emissions range from +10% to -23% of the baseline estimate.
Natural gas versus coal utilization in the electric sector represents a key
tradeoff, particularly under conservative assumptions about future technology
innovation. The lowest emissions scenarios are produced when the cost of
natural gas and electric vehicles decline while coal and oil prices increase
relative to the baseline.
