Historical responsibility for greenhouse gas emissions lies with the richest countries which have collectively used 90 percent of the total global carbon budget most scientists consider to be the limit beyond which we must not go.
The historical emissions of the poorest countries and the poorest 1 billion people is negligible, at about 3 percent of the total global budget. The UK is near the top of the league when considered on a per capita historical basis and even now, its 60 million people emit more than the 472 million people of Egypt, Nigeria, Pakistan, and Viet Nam combined.
The top five biggest present emitters responsible for more than 50 percent of world emissions are United States, China, India, Japan and Russian Federation. United States alone is responsible for one fifth and the top ten are responsible for more than 60% of total emissions.
The population of New York State (19 million) emits more than the population of 50 least developed countries (766 million).