Some major airline companies are committing to dramatically reducing the prodigious amounts of heat-trapping carbon dioxide the industry emits into the atmosphere. Meeting that goal will be expensive and technologically challenging, but it’s still achievable, says Timothy Takahashi, a Fulton Schools aerospace engineering professor of practice. Huge batteries or hydrogen fuel cells are too heavy for larger planes to be feasible alternatives to CO2-emitting liquid fuels, he notes, but biofuels might do the trick if their production is increased significantly. The answer might be combining alternative fuels with flying planes higher in the atmosphere and making flights shorter, both of which would be more fuel-efficient, Takahashi says.