Forgot to mention it appears you still can't read Chapman's fatality graphs, because it appears that you still don't get that small impactors represent a very small portion of the threat.

A note for the weak minded: Lack of support for spending two orders of magnitude more money for achieving an objective than needed does not equal lack of support for the objective.

I'd support funding a large space based scope and the technical support needed on the ground to detect threatening NEA's of any size. I just don't think the public will when they realize how little threat objects much below 300 m pose. For this reason I would place priority on the 300 m objective first rather than get bogged down in a prolonged battle to get funding for the 100 m objective. I think a better strategy for the 100 m class objects is to piggy back it on one of the large space observatories planned in the near future rather than attempting a stand alone justification.

There is a reason the lower limit for PHA's is set at magnitude 22 (about 200 m). The effects drop off rapidly below 300 m (blast strength is inversely proportional to diameter cubed). They drop off rapidly below 1 km as well, but I think most people can be convinced that impact tsunami's represent a significant threat. Even the smallest threatening impactors can take out a city with a direct hit, but the odds of this are so low that most will not take it seriously when compared to other preventable causes of death.

Unfortunately, most people take a fairly relaxed attitude to "small" risks when it involves personal pleasure or their tax dollars as demonstrated by the number of smokers and limited funding for control of rare or preventable diseases.

One of the things that discussions with EP has convinced me is that our current system is inadequate with regard to small impactors. Being able to detect them at near approach distances (which EP incorrectly denies) and being able to detect them rapidly and efficiently enough to afford reasonable protection are not the same thing.

Regards,
Mark