Planetary Defense Coordination Office Proposed to Fight Asteroids

Yahoo link from October 20, 2010 is no longer working.

And the SPACE.COM link is working.

Planetary Defense Coordination Office Proposed to Fight Asteroids
By Leonard David
SPACE.com's Space Insider Columnist
posted: 19 October 2010
01:58 pm ET
www.space.com...

Planetary Defense has been in the planning stages since 1993.
There was a report called SPACECAST 2020 Technical Report Volume I PREPARING FOR PLANETARY DEFENSE: Detection and Interception of Asteroids on Collision Course with Earth

www.fas.org...

This looks like it is now off the planning table and a reality:

www.rt.com...

NASA state thay have already identified 90% of the near earth asteroids over 1km (presumably in either width, length or height), but only 25% of those that are 140m or larger.

I am wondering what a 140-1000m sized asteroid impact would do to earth... I have seen estimates that say the impact that wiped out the dinosaurs was from an asteroid 6km in size (again presumably in diameter across one axis).