In case of a major disagreement of two nuclear armed countries, we are going to be much worse than in medieval times, as predicted by Einstein.
However, I am very optimistic.I think that common sense will prevail and our sons and grandsons will fly better and better models in the future.
I burn my kerosene in my jets without any remorse, however as CO2 emissions are a real issue for the world, I try to minimize my footprint using alcohool in my car as much as I can, :-)