Can Objective Morals & Values Exist under Atheism?

Definitions: 

Objective – that something is true regardless of how many people happen to believe in it.

Moral Values – the standards of good and evil — these govern an individual’'s behavior and choices (generosity is good; murder is bad; lying is bad; etc.).

Moral Duty – something that is obligatory or necessary for human beings to do. For example: one SHOULD be generous; one SHOULD NOT steal.

Moral Accountability  – means that there will be consequences and retribution when someone does not act ethically and morally. 

The last three are impossible under atheism. Under atheism, no objective morality exists because each person's moral values are just their own opinion, and there is nothing that can establish which opinion is correct over all others. In fact, under atheism, humans are just another animal species with their own social species culture, and morality is just an illusion.

Under atheism — even if you could argue that there was an Objective Morality, i.e. generosity is good, murder is bad - there is still no concept of moral duties. This is because there is nothing in an atheist worldview that objectively REQUIRES a person to practice goodness and act ethically. 

Finally, even if you somehow established Objective Moral Values and Objective Moral Duties under atheism, in the end there is no Moral Accountability. The person who lives a good life and the person who lives an evil life — under atheism — meet the exact same fate because they cease to exist after they die.

"What has been called the permissive society where anything goes, nothing matters, nothing is sacred or private any more, is not a promising foundation for a brave and upright new world. This fearful chase after material ease must surely be tempered by peace of mind, by conscience, by moral values, which must be resuscitated…."

– Imam Shah Karim al-Husayni Aga Khan IV,   
Peshawar University Convocation Ceremony (Peshawar, Pakistan), November 30, 1967 

"A passion for justice, the quest for equality, a respect for tolerance, a dedication to human dignity —  these are universal human values which are broadly shared across divisions of class, race, language, faith and geography. They constitute what classical philosophers, in the East and West alike, have described as human “virtue” — not merely the absence of negative restraints on individual freedom, but also a set of positive responsibilities, moral disciplines which prevent liberty from turning into license."

– Imam Shah Karim al-Husayni Aga Khan IV,   
School of International and Public Affairs, Columbia University, Commencement Ceremony (New York, USA), May 15, 2006