Six Greenpeace activists scaled a massive chimney at Poland's Belchatow coal-fired power plant on Tuesday and will remain there overnight, as one of Europe's largest polluters gears up to host the COP24 climate summit.
The protesting climbers "have the appropriate equipment to spend the night in difficult conditions," Greenpeace said in a statement.
In total nine activists from around the world scaled the 180-metre (560-foot) tower as part of a Greenpeace campaign aimed at phasing out coal use.
"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.
"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."
Maciej Szczepaniuk, 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 programme 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 United States -- 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 global warming is on track to surpass three degrees by 2100 and urge governments to do more than first planned to rein it in.
One of the Greenpeace activists who climbed a 180 metre-high chimney at Poland's Belchatow coal-fired power plant