According to the study ''Dirty Thirty'', issued in May 2007 by the World Wide Fund for Nature, Prunéřov Power Station is the twelfth-worst power station in Europe in terms of the relation of energy efficiency to carbon dioxide emissions.<ref>[http://assets.panda.org/downloads/european_dirty_thirty_may_2007.pdf The ''Dirty Thirty'' report]</ref> The power station is the largest single source of CO2 in Czech Republic. In 2008 it emitted 9,210 millions of metric tons of CO2.<ref>[http://www.irz.cz/vyhledavani-v-registru/historie/CZ34736841/2008 Integrovaný registr znečišťování]</ref>
==Unit 2retrofit==In 2010 [[CEZ]] announced plan to modernize unit 2retrofit the power station. CEZ said that, with the refit, the power station would keep operating until about 2035; otherwise it would close in 2020. This The plan was challenged by Micronesia on the grounds that the expansion of the power station has impact to the climate and through this to the environment of Micronesia. Micronesia requested a Transboundary Environmental Impact Assessment.<ref>[http://www.upi.com/Science_News/Resource-Wars/2010/01/19/Micronesia-challenges-Czech-coal-plant/UPI-82581263927614/ Micronesia challenges Czech coal plant]UPI, Jan 19, 2010</ref> According to the Czech environment ministry that modernization plan does not include best available technology.<ref>[http://portal.gov.cz/wps/portal/_s.155/7226/_s.155/10202?docid=120244 Navrhovaná technologie pro modernizaci Prunéřova II není dostatečná]</ref>
On January 26 2010 Czech minister of the Environment Jan Dusík informed he was calling in international experts to carry out an environmental impact assessment of plans to modernize the power station.<ref>[http://www.radio.cz/en/article/124449 Environment Ministry calls in international experts to sidestep pressure over controversial power plant], Český rozhhla Radia Praha, 27. 1. 2010</ref> In March 2010 he publicly released the report from Det Norske Veritas, that proved lack of best available technology in the CEZ plan EIA.<ref>[http://www.enviweb.cz/clanek/eia/81184/ DNV´s Prunéřov assessment shows deviations]</ref> Shortly after Minister Dusík resigned, while claiming he was under pressure from prime minister Jan Fischer (politician) to approve CEZ plan EIA.<ref name=pp>[http://www.praguepost.com/news/4272-compromised-minister-set-to-approve-coal-plant-expansion.html Compromised minister set to approve coal plant expansion]</ref> As a result the Green party also withdrew his second minister from government. After short led by Minister of Agriculture Jakub Šebesta former CEZ employee Rút Bízková was appointed as Minister of the Environment and after two weeks in office he approved CEZ plan EIA in April.<ref name=pp/>