Can objective morality exist in Atheism?

[Purple Rabbit]

If Atheism obtains (God does not exist) is there a source for morality other than oneself that is objective?

The term objective morality is a contradiction because morals are about something and what that something is matters to what "moral" means. If morals were objective they should apply in all possible universes and contexts. This means they should apply not only to human relations and human behaviour but also to aliens, gravity, electrons and protons smashing into each other in the LHC.

Moral codes can serve the purpose to regulate behaviour in social groups. By definition this means that the moral we know of, the one described in literature and legislation, is relative to humans. At all times individuals in a group can adopt or reject some or all moral codes that prevail in a group. It also is subject to cultural differences of which differences in legislation across the globe testify.

The idea that moral is objective is not only a misconception but also a cop out for critical thinking on just and fair behaviour.