Carbon trading creates a financial consequence for countries that fail to reduce their pollution output, which is necessary in order to enforce lower emissions on a global scale. Because the entire Earth is a single interconnected ecosystem, a global effort to protect the environment is the only effective means of doing so. Carbon trading is one way to encourage countries that are causing environmental problems for the world to make an effort to clean up.
Cap and trade would seriously inhibit job creation and energy production in the US; it is also based on faulty scientific premises. Cap and trade would send home energy costs sky high and cause an enormous crunch in household budgets. Additionally, you cannot create a market for trading clean air; it just doesn't work and is totally silly. It has buckled in Europe. Furthermore, this idea is founded on faulty science. The earth and its environment have been changing since it was created; creatures come and ago, thrive and founder, today just as they have throughout time. The idea that somehow charging company for their emissions is going to improve the environment is very misguided. Charging them is going to cost everyone - the companies, the job holders, and the American people as energy prices necessarily skyrocket.