The experience from jurisdictions that have implemented carbon prices shows the policy does reduce emissions. B.C. saw per capita fuel use covered by the tax dropping 16% by 2014, relative to 2008. It works by sending market signals that guide both consumption choices and long-term investment decisions towards low-carbon alternatives; and it gives the province the opportunity to invest the revenues into green energy programs, renewable energy projects and programs to reduce the consumption of energy. There's also the option of providing rebates, particularly to lower income people who might be unduly impacted by it. On the whole, from studies in about 40 countries and 20 subnational regions, things are going very well.
On September 26th, 2018. See this statement in context.