Agreed ( but being done at this time by many here) )

You seem to be looking at trying to account for effects of past impacts- I am concerned with the possible effects of a future impact. If the earthquakes that follow said impact kills off the survivors of the impact, that does not mean we should not be looking at ways of preventing the impact itself.

The effects I am discussing are those that WOULD happen in the event of a major impact. The particulate dispersion into the atmosphere, the tsunami effects, the shock wave, the transfer of heat from the c9ollision can all be calculated and modeled- THEY would have a major effect. There would be other effects not now well modeled- volcanoes, crustal motion, etc, but what we KNOW would happen is enough to worry about