Re: This is science . . . ?
Speculation, at best.
Seems Dr. Lal would first need to verify whether the same number and types of aircraft would have been operating anyway in military training exercises around the world, and what effect (if any) they would have had, based, of course, on what is already known of the effect from decades of war-games, both inter-branch and international.
Methinks the good doctor may have taken a step or two from his proven field of research,
Dan (the paper given isn't quite long enough to run the required analyses)