As of 2018, seventy national and sub-national jurisdictions
worldwide have either implemented or scheduled carbon pricing programs. Their
combined emissions represent approximately 20% of global greenhouse gas
emissions. This list includes ten U.S. states, Canada, Mexico, China, and
Europe. The total value of the carbon priced under these initiatives exceeds $79
The first use of a
cap-and-trade system was in the 1990s in the U.S. to address sulphur dioxide emissions
responsible for acid rain. Today, nine Northeast and Mid-Atlantic states
participate in the Regional Greenhouse Gas Initiative (RGGI), an emissions
trading program to reduce greenhouse gas emissions in the power sector. Other
states are now looking to join RGGI and RGGI states are exploring an extension
of the program to include transportation emissions. California launched its
cap-and-trade program in 2013 as part of the larger Western Climate Initiative.
It covers emissions from transportation, industry, and the power sector.