If another KT impact were to happen today, it would cause another Snowball Earth

[Count Iblis]

http://www.snowballearth.org/could.html"

On the other hand, a climate model predicted that if the 10-km-diameter asteroid that hit the Earth 65 million years ago extinguishing the dinosaurs and many marine lineages hit instead today, a snowball Earth would result. This is because the present cold ocean is more susceptible to surface freezing than the warm Cretaceous ocean (when a snowball Earth did not occur) during the decade of reduced Solar forcing due to dust thrown up by the impact

 

[Andre]

I wonder about the scientific level of such statements. First of all, a warm Cretaceous ocean is a hypothesis, based on suppositions. No matter how sophisticated, it cannot be proven.

Second, the rate at which the atmosphere cleans after a disturbance is not dependent on the amount of debris but on atmospheric density, particle size and gravity, which can easily been demonstrated with different volcanic outbursts. The bigger particles settle within a year (Mount Tambora eruption 1816 - The year without summer) while the smallest aerosol particles remaining airborne for about 3-4 years (Pinotuba eruption 1991). Therefore it is rather uncertain if atmospheric disturbance is long enough to create a "snowball earth". Regardless if now or during the Cretaceous.

Hence statements like that are highly speculative and can never be tested, so why bother and hence the challenge of the scientific level.