Brett Ruston, California

Although the total contribution of CO2  generated by commercial airliners is 2.8% the effect is much greater due to the altitude at which the CO2  is generated and condensation trails, which form under certain fairly common conditions. These two parameters act like a warm blanket trapping heat that would have otherwise escaped into space. In addition, airlines are allowed to jettison their fuel when emergency landings are required to lighten the load before landing. I have witnessed this first hand while outside under the flight path of the desperate crew. Unfortunately, airports have also routinely made the mistake of dousing mock or real airplane fires with fire-fighting foam containing the PFAS forever chemicals. When we factor in all of the harm that PFAS chemicals have done to our freshwater wells near airports and consider the ease at which virulent viral pathogens can skip across oceans to infect new continents one has to consider if a more reasonable option is available. I used to fly because I was limited by vacation time off from work. Since then, I have had much more time to explore my home continent and I have discovered amazing places that rival any offshore destination. Perhaps when electric short range planes become more available and people learn to appreciate backyard gems this part of the equation will be solved.