The article addresses carbon pricing tools like taxes and emissions trading systems to reduce greenhouse gas emissions. They examine how effective these instruments are in cutting emissions. By looking at existing carbon taxes and ETSs, they found that emissions subject to ETSs have generally decreased over time, while emissions under carbon taxes varied. Most carbon tax rates are low compared to what's needed to meet climate goals. ETSs have had surplus allowances, but measures have been taken to reduce them. Both ETSs and carbon taxes are often used together to target emissions. ETS designs have been improved based on experience sharing, but carbon tax designs have not evolved much. It was also noted that other policies alongside carbon pricing affect greenhouse gas emissions in all jurisdictions using these instruments.