
Sending rockets into space diminishes the planet's mass slightly; meteors add to it. There's a list of things that might make a difference, but the list is small, and the difference is smaller.
( , Fri 13 Jul 2012, 9:59, Reply)

trickle down to the earth as dust, and add about 25 tonnes each day.
( , Fri 13 Jul 2012, 17:45, Reply)