"The climate is already more disruptive than any activists can possibly be," said a spokesperson for Extinction Rebellion.

New York, September 8 (RHC)-- A group of climate activists wearing shirts that read "End Fossil Fuels" delayed the semifinal match of the U.S. Open Tennis Championships by around 45 minutes Thursday night in an effort to call greater public attention to the planetary emergency that is wreaking deadly havoc worldwide.

One of the demonstrators glued his bare feet to the concrete in the stands at New York City's Arthur Ashe Stadium, requiring additional effort by medical personnel and police to remove him and take him into custody.

The protesters were associated with the climate group Extinction Rebellion NYC, which said in a statement Thursday that there is "no tennis on a dead planet."

"The climate and ecological crisis threatens everything on our planet, including sports," the group said. "This action and similar actions are the response of a movement that has no other recourse than to engage in unconventional means of protest to bring mass attention to the greatest emergency of our time."

Nineteen-year-old Coco Gauff won the semifinal match after it resumed. In an interview following her victory, Gauff said she supports "preaching about what you feel and what you believe in."

"It was done in a peaceful way, so I can't get too mad at it," she said of the demonstration. "Obviously I don't want it to happen when I'm winning up 6-4, 1-0, and I wanted the momentum to keep going. But hey, if that's what they felt they needed to do to get their voices heard, I can't really get upset at it."

The U.S. Open—which counts JPMorgan, a major funder of fossil fuels, as an official partner—kicked off late last month amid growing concerns about the impact of extreme heat on the sport.

During a match earlier this week, Russian player Daniil Medvedev looked into a courtside camera between points and warned that an athlete is "gonna die" from the scorching temperatures.

The Associated Pressreported that "it got so hot and humid at the U.S. Open on Tuesday that the folks in charge adopted a new policy for the rest of this year's tournament: They will partially shut the Arthur Ashe Stadium roof in extreme conditions to offer some extra shade."

"An Associated Pressanalysis showed the average high temperatures felt during the U.S. Open and the three other major tennis tournaments steadily have gotten higher and more dangerous in recent decades, reflecting the climate change that created record heat waves around the globe this summer," the outlet noted. "For athletes, it can keep them from playing their best and, worse, increases the likelihood of heat-related illness."

Earlier this week, the European Union's Copernicus Climate Change Service confirmed that this summer has been the hottest on record, and a separate global report led by the U.S. National Oceanic and Atmospheric Administration showed that greenhouse gas concentrations hit a record high last year as fossil fuel extraction continued.

A recent survey found that experts on social movements believe disruptive protests of the kind launched by Extinction Rebellion are important to the success of a particular cause, even though the initial public reaction to such tactics can often be negative. The U.S. Open protest drew loud boos from attendees.

Miles Grant, an Extinction Rebellion spokesperson, said Thursday that "the climate is already more disruptive than any activists can possibly be."

"Just look at the U.S. Open and other big tennis events—year after year, the average temperatures have been rising, making it hotter and more dangerous for the players and spectators," said Grant. "At some point, there will be fewer outdoor sporting events due to excessive heat."