The Greenpeace protesters climbed the 180m high chimney at the Belchatow power plant.
Greenpeace protestors on Tuesday scaled a massive chimney at Poland's Belchatow coal-fired power plant as one of Europe's largest polluters gears up to host the COP24 global climate summit.
"We want to draw the world's attention to the fact that climate change is real, that human tragedies are taking place before our eyes and that action is urgent," Greenpeace Poland activist Katarzyna Guzek told AFP via telephone.
She said nine activists from around the world had scaled the 180 metre tower as part of a Greenpeace campaign aimed at phasing out coal use.
"Belchatow is the largest coal-fired power station in the EU, one of the largest in the world and therefore the symbol of a system that kills life on our planet," Guzek added.
The activists were prepared to remain on the tower "for some time", Guzek said but refused to go into detail.
Maciej Szczepaniuk, a spokesman for Poland's PGE power group which owns the Belchatow facility in southern Poland told AFP that the "protest action has no impact on the functioning of the plant".
Delegations from nearly 200 countries will meet in the nearby Polish coal city of Katowice for the two-week COP24 summit which opens on Sunday.
Calling Poland a "major contributor to global warming", Guzek said: "On the one hand it is organising the summit and on the other hand it is announcing its energy program in which coal remains a staple fuel until 2060."
The UN's climate chief Patricia Espinosa insists the summit in Poland must produce a detailed programme to move the Paris climate accord forward.
World leaders have been trying to breathe new life into the 195-nation Paris Agreement amid backsliding from several nations - most notably the US - over commitments made when it was signed in December 2015.
It is to take effect in 2020 and calls for limiting global warming to less than two degrees Celsius above pre-industrial levels.
Experts warn that the global measure is on track to surpass three degrees by 2100 and urge governments they must now do even more than first planned if global warming is to be reined in at all.