One of the ways of implementing the concept of sustainable development by the European Union is their energy policy. Among the three main objectives in its energy policy is a reduction in greenhouse gases (mainly CO2) emissions to at least 20% below 1990 levels by 2020. This study aims to assess the impact of international trade on actual CO2 emission in the EU, China and the USA for the period 1997–2017. For this aim, the Actual-Open CO2 emissions were calculated, taking into account the transfer of CO2 in exported products and services from China and the USA to the EU and vice versa. It is concluded that the actual CO2 emissions in China, the USA, and the EU differed from the traditionally calculated emissions. This has serious consequences for policy, as the factual level of implementation of the EU energy policy goals may be different from what is assumed. Without including the goals of energy policy into trade policy, the effectiveness of measures may be limited. This also has implications for the effectiveness of environmental management systems. When improvements rely on increasing trade with large CO2 emitting countries, the final effect may be opposed to the assumed effect.