The European Union left Poland out of a 2050 climate neutrality agreement on Friday after hours of summit discussions with three poorer eastern member states that demanded more funds for economic transition and support for nuclear power.
The Czech Republic and Hungary eventually dropped their resistance after winning a guarantee that nuclear energy would be recognised as a way for EU states to reduce greenhouse gas emissions. But Poland remained against.
A "man on the moon moment"
The tussle came a day after Germany's Ursula von der Leyen, the new head of the bloc's executive European Commission, proposed a 100-billion-euro ($110 billion) investment plan for net-zero greenhouse gas emissions by mid-century, declaring it Europe's "man on the moon moment".
The European Union's new push comes as popular protests demanding more action to fight climate change spread around the bloc.
Von der Leyen said the Brussels summit deal, reached in the early hours of Friday by 27 national EU leaders, was enough for the commission to start rolling out concrete climate legislative proposals for the bloc next year based on the 2050 goal.
"We acknowledge that the transition is a big one for Poland," she said. "It needs more time to go through the details, but this will not change the time frame ... for the commission."
"Very difficult" negotiations
Polish Prime Minister Mateusz Morawiecki, whose country relies on coal for some 80% of its energy needs, said the negotiations had been "very difficult".
"Poland will be reaching climate neutrality at its own pace," he told reporters after the marathon talks.
German Chancellor Angela Merkel said she was satisfied with the outcome.
"There is no splitting of Europe into separate parts but one member state needing more time to see how it will be implemented," she said.
Warsaw's discussions about introducing nuclear energy in the largest ex-communist EU country have not yet been settled, partly due to high costs.
The neighbouring Czech Republic and Hungary want to invest in nuclear energy and won a line in the EU leaders' tortured decision specifically recognising their right to do that, despite opposition from Austria, Luxembourg and Germany.
Poland had demanded more specific guarantees on the scale and scope of financing for phasing out fossil fuels, which ties into another difficult debate in the bloc on its next budget for 2021-27. On Thursday night, EU leaders meeting in Brussels only agreed to postpone that discussion until 2020.