17 EU nations signed letter warning of ETS2's sharp energy price surges. Propose 7 changes to ease social fallout. Demand regular ETS2 emission statistics publication. Require emission unit price forecasts to cut uncertainty. Seek Market Stability Reserve tweaks to dampen price spikes. Want reserve extension beyond 2031. Push stronger price management mechanisms. ETS2 taxes fossil fuels in transport and buildings. Polluter-pays principle hikes coal 500 zł per ton. Petrol rises 60 grosze per liter. Czech PM Petr Fiala announces qualified majority backing. Estonia's Laura Remmelgas says Commission must legislate changes. More countries may join appeal. ETS2 aims for 55% emission cuts by 2030 and climate neutrality by 2050. Covers hard-to-decarbonize sectors previously outside ETS1.