More than 100 flights were canceled on Thursday at Germany’s busiest airport, Frankfurt, as environmental activists initiated a coordinated effort to disrupt air travel across Europe during the peak of the summer holiday season. The protests aim to highlight the urgent threat of climate change.

Frankfurt Airport officials reported that flights were halted for safety reasons after climate activists breached security fences, prompting a response from police, firefighters, and airport security. Although all runways were back in operation by 7:50 a.m. local time, approximately 140 flights had already been canceled, with further disruptions anticipated throughout the day.

Environmental groups announced plans to target airports across Europe this summer, drawing attention to the link between fossil fuels, such as those used by airplanes, and climate change. These groups are urging global governments to cease the extraction and burning of fossil fuels by 2030. “We sharply condemn these unauthorized demonstrations, and we reserve the right to take legal action against the participants,” stated Frankfurt Airport. “Their activities pose severe danger to flight operations — possibly putting human life at risk.”

Climate data recently revealed that Monday marked the hottest day ever recorded, as human-induced climate change continues to drive unprecedented heat and extreme weather. Despite global pledges to reduce fossil fuel usage, the International Energy Agency projects a 7% increase in global investments in planet-warming oil and gas this year. The aviation industry, one of the most carbon-intensive sectors, is expected to grow steadily over the coming decades.

The Last Generation group, which organized the Frankfurt demonstration, reported that six protesters cut holes in the perimeter fence and entered the runways on foot, bicycles, and skateboards. This was the second consecutive day of airport disruptions in Germany, following a similar protest at Cologne-Bonn Airport on Wednesday that resulted in 31 canceled flights. Similar actions took place in Finland, Norway, Switzerland, and Spain, with varying degrees of disruption.

In response to these protests, the German Cabinet recently approved legislation to impose tougher penalties on individuals who breach airport perimeters. The proposed bill, which requires approval by lawmakers, includes punishments of up to two years in prison for intentionally intruding on airside areas of airports or endangering civil aviation. Currently, such intrusions result only in fines.

Environmental activists remain steadfast in their mission, emphasizing the critical need for immediate action to address the climate crisis and reduce global reliance on fossil fuels.