The goal of this paper is to analyse the volumes of greenhouse gas (GHG) emissions from the European Union Emissions Trading System’s (EU ETS) participants in Latvia in relation to their participation therein. After describing and discussing the EU ETS mechanism and its operation in Latvia in the period 2005-2010, the interconnectedness between the GHG emissions and the EU ETS participants’ operation is analysed. The analysis concludes that, although the EU ETS has contributed towards GHG emission reduction, due to the growth of the economy, overall GHG emissions from the EU ETS participants in Latvia are increasing.