The German government on Friday announced that it will swiftly adjust its law aiming to curb climate change, after the country's top court ruled that existing legislation places an unfair burden on younger generations.

Germany's Constitutional Court said Thursday that the government must set clear goals for reducing greenhouse gas emissions after 2030. The verdict was a victory for campaigners, who had argued that the measures put forward so far are insufficient to meet the Paris climate accord's goal of keeping global warming well below 2 degrees Celsius (3.6 Fahrenheit), ideally no more than 1.5 C (2.7 F) by 2100.

“This is a big victory for the young people who filed the lawsuits,” government spokesman Steffen Seibert said, but added that the court had approved the basic principle behind legislation passed two years ago.

The climate law details how the country will cut its greenhouse gas emissions by 55% from 1990 levels over the next decade, but not for the period from 2031 to 2050, by when Germany wants to stop emitting more than can be captured through natural or technological means.

“The German government will now do everything to propose a law in this legislative period to implement the core points of the verdict,” Seibert said, adding that Cabinet would discuss the issue in the coming week.

Climate activists have described the verdict as a “slap in the face” for the German government and Chancellor Angela Merkel, who isn't running for another term in September's federal election. Merkel was Germany's environment minister from 1994 to 1998, and championed combating climate change as chancellor from 2005 onward, though critics say she often went easy on domestic polluters.

A spokesman for the Environment Ministry said proposals for adjusting the law would include “a fair distribution of the climate protection efforts among the generations,'' but rejected the idea of adopting a fixed carbon budget' cited by the court.

''Paris expressly agreed on a different approach,” Nikolai Fichtner said, adding that the idea of gradually increasing ambitions agreed in the French capital six years ago was better than a fixed budget, which could lead to abrupt disruptions for German industry.