A Dutch court rules that Shell must step up its climate change efforts.

A Dutch court ruled Wednesday that Royal Dutch Shell, Europe’s largest oil company, must accelerate its efforts to reduce carbon dioxide emissions to tackle climate change.

The District Court in The Hague ruled that Shell was “obliged” to reduce the carbon dioxide emissions of its activities by 45 percent at the end of 2030 compared with 2019.

Shell has already adopted targets for emissions reduction, but the terms of the court’s decision could require the company to substantially accelerate the process of reducing emissions-producing fuels like oil and gas.

At present, Shell says it hopes to achieve net zero emissions by 2050, with a series of interim targets along the way.

A spokesman said that the company expected to “to appeal today’s disappointing court decision.”

The ruling will likely only apply in the Netherlands, and it is unclear how it would be enforced. There was also a small consolation for Shell: The court found that the company’s current carbon dioxide emissions were not unlawful.

Still, the defeat of an oil giant by an environmental group — Milieudefensie, the Dutch wing of the Friends of the Earth, joined by other activists — appeared to represent a breakthrough in a court’s willingness to dictate to a major business what it must do globally to protect the climate.

“It really stands out,” said Eric De Brabandere, a professor of international law at Leiden University in the Netherlands, who was not involved in the case. “Clearly this will inspire other cases.”

However, he said, Wednesday’s decision was influenced by peculiarities of Dutch law — Shell is based in The Hague — and so might have limited relevance in other countries where environmentalists might launch suits against oil companies.

The Dutch court largely accepted the argument that Shell had a duty to move faster on emissions — especially to the people of the Netherlands, who could be at risk from rising sea levels and other dangers from climate change.

Essentially, the Dutch environmentalists are leaning on the courts to take action to reduce global warming, where they believe the government has not done enough.

“It’s pushing the judge into a position where he or she is influencing changes in the law or policy,” he said. “It goes beyond the traditional idea that the judge applies the law.”

The plaintiffs were jubilant after the victory.

“This ruling will change the world,” said Milieudefensie’s lawyer, Roger Cox. He predicted that people would now be “ready to sue the oil companies in their own countries based on our example.”

The environmentalists were taking on their country’s largest and most influential company.

“The court understands that the consequences could be big for Shell,” Jeannette Honée, a spokeswoman for the court, said in a video on the court website.

“But the court believes that the consequences of severe climate change are more important than Shell’s interests, ” she added.

The court also conceded that Shell had already taken numerous steps on climate change including subscribing to the goals of the 2015 Paris accords as well as the climate targets of the Dutch government. However, the court decided that such moves were not sufficient.

Shell’s “policy intentions and ambitions,” the court said, “largely amount to rather intangible, undefined and non-binding plans for the long-term.”

“Severe climate change has consequences for human rights, including the right to life. And the court thinks that companies, among them Shell, have to respect those human rights,” Ms. Honée said.

Shell argues that it recognizes the imperatives of dealing with climate change and that it is moving with appropriate speed. The company said that it already had an extensive program to reduce emissions, and that it is investing billions of dollars in low-carbon energy including hydrogen, renewables like wind and solar and electric vehicle charging.

“We want to grow demand for these products and scale up our new energy businesses even more quickly,” Shell said on Wednesday.