The pontiff has become the first leader of the Catholic Church to open a General Assembly of the UN.
He told delegates from hundreds of countries: "A selfish and boundless thirst for power and material prosperity leads both to the misuse of available natural resources and to the exclusion of the weak and disadvantaged."
He urged governments around the world to ensure people have enough to live: "In practical terms, this absolute minimum has three names: lodging, labour, and land."
Speaking about the poor he said: "They are cast off by society, forced to live off what is discarded and suffer unjustly from the abuse of the environment.
"They are part of today's widespread and quietly growing culture of waste."
In a speech covering several areas the Holy Father also urged for world nuclear disarmament.
He, again, gave a climate change warning: "The ecological crisis and the large-scale destruction of biodiversity can threaten the very existence of the human species."
"Any harm done to the environment, therefore, is harm done to humanity," he said.
Ahead of climate change talks in Paris in December he called for "fundamental and effective agreements".
The United Nations has called for easier access to contraception and abortion for woman. But Francis said world leaders had to respect life "in all its stages and dimensions".
He added they had to recognise the "natural difference between man and woman."
Francis was greeted on his arrival at the UN by Secretary-General Ban Ki-moon, a key supporter of his eco-friendly agenda. In his opening remarks, Mr Ban praised Francis for his moral leadership.
"You are at home not in palaces, but among the poor; not with the famous, but with the forgotten; not in official portraits, but in selfies with young people," he said.
While his visit marked the fifth time a pope has addressed the United Nations, the Vatican flag was raised for the first time just before Francis' arrival.
The General Assembly recently agreed to allow the UN's two observer states, the Holy See and Palestine, to fly their flags alongside those of the 193 member states.
After his speech the pontiff made his way to the 9/11 memorial, where two waterfall pools mark the outlines of the World Trade Centre's twin towers before they were toppled by the terrorist attacks of September 11, 2001.
He met relatives of some of the nearly 3,000 victims before heading below ground to the September 11 museum for an interfaith service.
