BRUSSELS — After an all-night negotiating session, European Union leaders agreed on Friday morning to cut net carbon emissions by 55 percent in the next decade from levels measured in 1990, overcoming the concerns of nations still heavily dependent on coal and taking a critical step in the effort to become climate-neutral by 2050.
European leaders, who are keen to position themselves as at the forefront of the global fight against climate change, had failed in October to reach a deal on an even less ambitious target of 40 percent.
But after an agreement on a $2.2 trillion budget yesterday evening — with billions earmarked for member states to spend on the transition to a greener economy — momentum for a consensus environmental policy gathered speed.
Shortly after dawn, Charles Michel, the head of the group of the E.U. leaders, announced the news on Twitter.
“Europe is the leader in the fight against climate change,” he wrote. “We decided to cut our greenhouse gas emissions of at least 55 percent by 2030.”
The decision on the new target comes just in time for the United Nations climate summit this Saturday, where it will be announced by Ursula von der Leyen, the president of the European Commission, the bloc’s executive arm.
Chancellor Angela Merkel of Germany said it was “worth losing a night’s sleep” over the climate deal. “I don’t want to imagine what would have happened if we hadn’t been able to achieve such a result,” she said during a news conference on Friday, following the meeting.
Still, the details and language in the agreement were kept vague after many hours of often tense negotiations, leaving it up to the commission to hammer out the specifics.
The overnight discussions on climate, which has been declared as one of the European Union’s top priorities, have been obstructed by the familiar divisions between the wealthier Western European countries pushing for more ambitious targets, and a handful of Eastern European states, led by Poland, that depend heavily on coal.
They fought for more detailed provisions on how Brussels would support them in the transition, asking for the new rules to take differing circumstances into account.
In a gesture toward Eastern European governments, the E.U. leaders decided the target has to be reached by the bloc collectively — effectively giving coal-dependent countries more time to transition their energy consumption. For the first time, emissions from forests and land use — which absorb more carbon dioxide that they emit — will be included in the target, which climate activists say might weaken the outcome.
The legal provisions that would ensure compliance still need to be worked out in coming months and the agreement has to be endorsed by the commission and the European Parliament, which has been pushing for an even more ambitious cut of 60 percent.
Five years after the Paris climate accords first brought together rich and poor countries in a politically binding agreement pledging to stem the rise of global temperatures, the European Commission laid out plans in March for a climate law that would make the bloc carbon neutral by 2050.
It is part of a wider policy package called the Green Deal.
But some climate activists expressed skepticism at the time, saying that it lacked intermediate goals and key details as to how the target would be turned into reality. The expectation is now that the 2030 target makes climate neutrality more credible, analysts said.
“European leaders have agreed a new target, with new money, and an outline of what will be needed to deliver,” said Manon Dufour of E3G, a Brussels-based climate research institute. “Now the work starts.”
European leaders viewed the deal as a significant achievement, especially given the rifts between nations that had been laid bare in the bitter struggle to pass the massive new budget.
Poland and Hungary had held that deal hostage, angry about a mechanism tying the funds to issues related to democratic backsliding and the rule of law. The European leaders broke the deadlock on Thursday evening with a compromise, carefully crafted by Germany.
“I know that there are also deep wounds between member states,” said Ms. Merkel on Friday, acknowledging the intricacy of the negotiations.
In the climate talks, Poland and Hungary — along with the Czech Republic and other heavily coal-dependent nations — said it was unfair that they be held to the same standard as other nations whose economies already drew on a wider mix of energy sources.
Those concerns were allayed by the decision to make the targets a collective responsibility.
“We have an agreement which on the one hand allows us to realize the E.U. target, and on the other creates conditions for a just transition of the Polish economy and the energy sector,” said Michal Kurtyka, Poland’s minister of climate and environment.
The meeting’s written conclusion declared that the target would be “delivered collectively” in “the most cost-effective manner,” adding: “All member states will participate in this effort, taking into account considerations of fairness and solidarity, while leaving no one behind.”