**6. Conclusions**

Recent commitments to sustainable development and mitigating climate changes made by most of the world's governments also found their way into the energy policy of the European Union, becoming the basis of its national energy efficiency targets for 2020 embedded in the Europe 2020 strategy. The Europe 2020 strategy and the 3 × 20 climate and energy package envisage the reduction of greenhouse gas emissions in EU Member States as well as increasing the share of renewable energy for enhancing energy efficiency. Due to the varying level of economic development, different objectives were set for different EU Member States, with the Czech Republic and Slovakia, which constitute the case studies employed in this paper, facing targets that were lower than that in the case of the more economically developed EU countries.

With regard to the above, one has to understand that climate targets were set in order to slow down or even reverse (albeit in the long run) the depletion of natural resources and preventing environmental degradation. In no way were these targets set with a purpose of halting the economic growth (especially when it comes to the economies in transition) but rather to help the countries in question to develop in accordance with the principles of energy efficiency and sustainable economic growth.

Both countries selected for our case study, the Czech Republic and Slovakia, experienced deep system transformation after the fall of Communism in 1989 that are apparent in the GDP, gross inland energy consumption and GHG emissions that constitute the measures of sustainable development used in our research. Our results indicate that it is quite unlikely that the planned increase in renewable energy is going to reach its targets for the Czech Republic and Slovakia (which is similar to the case of other EU Member States that joined after 2004) but it will be possible to reduce energy consumption and greenhouse gas emissions. This is, among other things, due to the fact that gross inland energy consumption and greenhouse gas emissions in the Czech Republic and Slovakia appear to be correlated. Greenhouse gas emissions are going down in both countries in question a little faster than energy consumption, but this pace is more rapid in the Czech Republic than in Slovakia.

In addition, it becomes apparent that implementation of GHG emissions in the Czech Republic and Slovakia may be at risk in case the proper energy policy is not maintained by the stakeholders and governments of the respective countries. Moreover, our findings show that regardless of the mix of fossil and renewable energy, the state of economic development and the geographical location of any EU Member States, a proper energy policy is required for e ffectively reducing energy consumption and greenhouse gas emissions. The energy intensity of Czech and Slovak economies increased in the early 2000s and then stabilized at a level about twice of the EU average. Our analysis of the energy intensity for the both countries in question shows that in the forthcoming years its value is likely to remain the same.

Overall, our results also demonstrate that maintaining a proper balance between economic development and environmental protection should be kept at all cost regardless of the position of the country. The cases of the Czech Republic and Slovakia scrutinized in this paper confirms that. Both countries have (common) Communist pasts but both underwent a spectacular economic transition and became Member States of the European Union. However, their story might be used by other EU Member States, both constituting the "core" EU and those that joined in 2004 or after. It might be also interesting to study the implications of Brexit and the shift of energy policies during and after the transition period for the United Kingdom. Further progress in maintaining a proper balance between economic development and environmental protection might be ensured by the decisive steps of the Czech and Slovak (as well as other EU) stakeholders and policymakers in terms of investments into renewable energy sources, modernizing the old energy sector and seeking for new solutions for sustainability and energy e fficiency.

**Author Contributions:** Conceptualization, J.B., W.S. and A.F.; methodology, J.B. and N.N.; validation, J.B. and A.F.; formal analysis, J.B. and W.S.; resources, N.N. and A.F.; writing—original draft preparation: J.B., W.S., A.F., and N.N.; project administration, W.S. and J.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** The paper received no funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
