A mild fall led to European Union Emissions Trading System (ETS) Carbon Dioxide quota prices to drop rapidly compared with summer's level, only to rise again in November, ERR reports.
Whereas on August 19, the ETS price of CO2 stood at a record €98.01 per tonne, by mid-September it had fallen to the €65-€70 range.
It remained at this level until October 21, since when price level has risen again, to over €70 per tonne.
On the last day of November, the ETS CO2 quota price stood at €84.7 per tonne, again back to August level prices.
Autumn's fall in the ETS price of CO2 fell in Europe was put down to warmer than expected third season, and lower energy consumption.
With winter here and energy consumption rising in line with that, we are back to the status quo in late summer.
Energy expert Marko Allikson told ERR that the colder weather creates a greater need for the use of fossil fuels, especially at gas and coal-fired power plants.
The changed security situation and the need to decouple fully from Russian energy sources will have also had its effect.
The EU ETS is the world's first major, and largest, carbon market and is aimed at combatting climate change.
Editor: Andrew Whyte, Marko Tooming