Is it true or false that dust raised by the impact of a meteorite on earth may have blocked the sun's ray for many years?

Anything that causes large amounts of debris and dust to
be thrown into the atmosphere will also block some of the suns rays.  So, it is a
completely plausible (possible) theory that meteors which have struck the Earth in the
past have caused this to happen.  The typical effect is that the amount of light energy
from the sun is diminished, the debris acting sort of like a filter, and the average
surface temperature of the Earth can be lowered if enough material is thrown into the
upper atmosphere.

As a modern day comparison, I live not
far from Mt. St. Helens, in Washington State, and when it erupted in 1980, millions of
cubic yards of ash and dust were thrown upwards of 50,000 feet in the air.  For almost
five year afterwards, the sunsets were a more brilliant red as the debris stayed in the
atmosphere that long.  That one event did not significantly change the Earth's
temperature, but a large enough meteor might.

Some theories
suggest ice ages have been caused by large enough impacts, along with the extinction of
most species on Earth.