The government of Germany's regional state of Brandenburg on Tuesday approved a plan by the Swedish utility Vattenfall to extract extra brown coal, or lignite, at an open-cast mine near Cottbus, starting in 2027.

The IG BCE trade union representing mining and energy workers welcomed the approval. Brandenburg's opposition Greens joined condemnation from environmental and rural groups by describing the expansion as a "historic mistake" in view of Germany's switch to renewables.

Some 800 residents near the Welzow-South mine will face resettlement because excavation of an extra 2,000 hectares will eliminate a village, Proschim.

Complexities in switch to renewables

The Brandenburg decision highlighted the complexities of trying to tackle global warming a day after the Barack Obama administration unveiled its toughest-ever US climate change efforts by ordering sharp cuts in carbon dioxide emissions from US power coal-fired power plants.

Brandenburg state premier Dietmar Woidke of center-left Social Democrats said his cabinet favored renewable power generation sources - such as wind and solar - but coal provided a "bridge," given Germany's nuclear shutdown by 2022.

"Brown coal is indispensable as a bridge into the era of renewable energy," Woidke said, referring to Germany's green energy expansion that delivers about 25 percent of the nation's power supply.

Four ex-communist Left party ministers in Woidke's coalition cabinet also voted for the mine's expansion, although in a 2009 referendum the party had called for an exit from the region's traditional brown-coal power generation.

The Left's caucus leader in the Potsdam regional parliament, Margitta Mächtig, defended Tuesday's go-ahead, saying her party wanted an exit from coal by 2040.

Millions more tons of CO2

Greens parliamentary leader Axel Vogel said the combustion of coal from the expanded mine would result in an extra 204 million tons of carbon dioxide being emitted into the global atmosphere.

In March, the regional government in Germany's western state of North Rhine-Westphalia decided to trim a planned expansion of the Garzweiler II brown coal mine northwest of Cologne but added that extraction would continue until 2030.

Germany's Constitutional Court ruled in December that lignite mining and the use of domestic raw materials overall was a matter for the government, although it said citizens' rights must be respected in terms of relocation and compensation.

Brown coal is often burnt in power stations located close to mines to minimize its tendency to combust spontaneously during transport. It also emits more carbon dioxide when burnt compared with other types of coal.

Vattenfall is a major operator of the open-cast mines remaining in eastern Germany's Lausitz extraction belt while in North Rhine-Westphalia the main operator is RWE.

ipj/rc (dpa, epd)