Global fires after asteroid impact probably caused mass extinction

[Emily]

http://onlinelibrary.wiley.com/doi/10.1002/2013EO200011/abstract

Balcerak, E. (2013), Global fires after asteroid impact probably caused mass extinction, Eos Trans. AGU, 94(20), 188.
Keywords:


About 66 million years ago, a mountain-sized asteroid hit what is now the Yucatan in Mexico at exactly the time of the Cretaceous-Paleogene (K-Pg) mass extinction. Evidence for the asteroid impact comes from sediments in the K-Pg boundary layer, but the details of the event, including what precisely caused the mass extinction, are still being debated

http://schillerlab.bio-toolkit.com/media/pdfs/2010/03/16/367033a0.pdf
Chapman, Clark R., and David Morrison. "Impacts on the Earth by asteroids and comets: assessing the hazard." Nature 367.6458 (1994): 33-40.

Of course, there is perhaps a much more serious indirect threat from small impacts: misidentification of an asteroid airburst could trigger an inappropriate military response from a nuclear power in a times of international tension...