A trading post was a place or establishment where the trading of goods took place; the term is generally used, in modern parlance, in reference to such establishments in historic Northern America, although the practice long predates that continent's colonization by Europeans. The preferred travel route to a trading post or between trading posts, was known as a trade route.
Trading posts were also places for people to meet and exchange the news of the world or simply the news from their home country (many of the world's trading posts were located in places which were popular destinations for emigration) in a time when not even newspapers existed.
European colonialism traces its roots to ancient Carthage. Originally a trading settlement of Phoenician colonists, Carthage grew into a vast economic and political power throughout the Mediterranean, accumulating wealth and influence through its economic (trading) prowess. Almost every city of importance of the world once started its history as a trading post: Venice, New York, Shanghai, Singapore, Hong Kong, Naples, Rotterdam etc.
Emissions trading or cap and trade is a government-mandated, market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants. Various countries, states and groups of companies have adopted such trading systems, notably for mitigating climate change.
A central authority (usually a governmental body) allocates or sells a limited number of permits to discharge specific quantities of a specific pollutant per time period. Polluters are required to hold permits in amount equal to their emissions. Polluters that want to increase their emissions must buy permits from others willing to sell them.Financial derivatives of permits can also be traded on secondary markets.
In theory, polluters who can reduce emissions most cheaply will do so, achieving the emission reduction at the lowest cost to society. Cap and trade is meant to provide the private sector with the flexibility required to reduce emissions while stimulating technological innovation and economic growth.