In the United States, the current carbon market at the Chicago Climate Exchange buys offsets or "pollution credits" as some have called them. The amount of carbon sequestration purchased is directly related to emissions of carbon into the atmosphere by industries, for example. As the trading price of carbon offsets increases, presumably emissions will go down, but then so will the purchase of offsets.
Will reducing carbon dioxide emissions slow down global warming? Hardly, according to the Intergovernmental Panel on Climate Change. "Complete elimination of CO2 emissions is estimated to lead to a slow decrease in atmospheric CO2 of about 40 ppm over the 21st century" (IPCC Fourth Assessment FAQ, section 10.3).