To rework in a new way what I wrote regarding Parshat Tazria:
For 7 days after the birth of a boy, a mother is in a biblical state of Tumah, followed by 33 days of what is called Dam Tohar, or pure blood. After the 7 days are over, the Brit Milah takes place. One of the reasons given is that the Brit Milah is a celebration, so therefore it takes place when the father and mother are no longer sad that they can't have any physical contact.
6000 divided in to 40 days (7+33) = 40 days of 150 years.
7 * 150 = 1050.
Adam HaRishon's sin caused the earth to be cursed. This curse was lifted at the time of Noach's birth, which as can be seen here, was in the year 1056, just over 1050 years after the sin, the beginning of the 8th Day. And then the land began to give forth again. There are other parallels that one could draw from this, but I will leave it here.