To comply with a Dutch court order to cut carbon emissions, Royal Dutch Shell RDS.A -0.82% PLC may have to overhaul its business and cut its oil output faster than it had planned, analysts and investors said. Potential ways to curb emissions include selling assets, rethinking exploration spending and halting growth of its liquefied-natural gas operations, they said.

Shell faces the potential upheaval after the district court in The Hague on Wednesday ruled that the company is partially responsible for climate change and must reduce its carbon emissions by 45% by 2030, compared with 2019 levels. That target, which was called for by the environmental groups that brought the case, is in line with United Nations guidance for member states aimed at preventing global temperatures rising more than 1.5 degrees Celsius above preindustrial levels.

Shell said it was disappointed and fully expected to appeal the decision, and that it is already investing billions of dollars in low-carbon energy, including electric-vehicle charging, biofuels and renewables.

“We are carefully reviewing the court’s written judgment and the questions it raises,” a Shell spokeswoman said.

Activists celebrated the verdict of the court case against Shell in The Hague, Netherlands, on Wednesday.

PHOTO: PETER DEJONG/ASSOCIATED PRESS

If Shell pursues an appeal, the case would be referred to a court of appeal where it can take around one to two years to be heard, after which it can be further appealed in the Dutch supreme court. The court on Wednesday said its order would stand provisionally, despite acknowledging potentially far- reaching consequences for Shell that may be difficult to undo. “If Shell are going to hit those 2030 targets that have been imposed on them, they need to start acting now,” said Nick Stansbury, head of climate solutions at Legal & General Investment Management, the U.K.’s largest asset manager and a Shell shareholder.

“The range of things they could do is big,” he said, suggesting options could include selling or spinning off assets. Mr. Stansbury said that while Shell may be able to successfully appeal the Dutch ruling, the pressure to reduce emissions would remain and that he expected there to be other courts considering the same issue.