Step-by-step explanation:

Although population growth in the 20th and 21st centuries has skyrocketed, it can be slowed, stopped and reversed through actions which enhance global justice and improve people's lives. Under the United Nations’ most optimistic scenario, a sustainable reduction in global population could happen within decades.

We need to take many actions to reduce the impact of those of us already here – especially the richest of us who have the largest emvironmental impact – including through reducing consumption to sustainable levels, and systemic economic changes.

One of the most effective steps we can take to reduce our collective environmental impact is to choose smaller family size, and empower those who can't make that choice freely to do so.