Washington  - World governments agreed Friday to limit tourism to the Antarctic in an effort to protect the region's fragile ecosystem, which participants warned has been feeling the effects of climate change more than any other part of the globe.

The 28 members of the Antarctic Treaty Consultative Meeting unanimously agreed to restrict to 100 the number of tourists that could be on the Antarctic's shores at any one time, as well as limiting cruise ships travelling to the region to 500 passengers each.

The measures, which still have to be ratified by the members, had been pushed by the United States, which hosted the nearly-two week summit in Baltimore. Secretary of State Hillary Rodham Clinton, who opened the summit last week, had warned that protecting the region was crucial to stabilizing the global climate.

Gerald Leape of the Pew Environment Group, a US-based climate group, welcomed the new restrictions but said they did not go far enough to limit tourism. He pushed for an annual cap on the number of people that visit the poles, rather than just limits on ship passengers.

"Visiting Antarctica should be a privilege. It's not a right," Leape said in an interview.

The summit also agreed to new safety rules for ships travelling to the poles and reviewed the latest science on climate change's impact. Two US studies released ahead of the conference suggested polar ice was melting faster than expected as global temperatures rise.

Tucker Scully, who chaired the conference, said monitoring the poles was providing an "understanding of the changes that are taking place in the global climate."

The gathering marked the first US-hosted summit on the environment since President Barack Obama took office in January, and comes as world governments are hoping to reach a new deal by December to curb the pollutants that cause global warming. (dpa)