“Out here in the middle of the Pacific Ocean, climate change has arrived,” Marshall Islands president Christopher Loeak says in a video address to be released globally on Friday, ahead of Sunday’s People’s Climate March and next week’s UN Climate Summit.

Standing in front of the brick seawall he built to protect his home from the rising ocean, Loeak describes how his atoll nation, population 52,634, “is at the frontline in the battle against climate change.”

“The beaches of Buoj where I used to fish as a boy are already under water, and the fresh water we need to grow our food gets saltier every day,” he says, as waves crash in the background. “As scientists had predicted, some of our islands have already completely disappeared, gone forever under the ever-rising waves. For the Marshall Islands and our friends in the Pacific, this is already a full-blown climate emergency.”

While some Pacific Island communities are considering, or have settled on, relocation in response to rising sea levels, Loeak rejects such an option.

“These islands are our home,” he says. “They hold our history, our heritage and our hopes for the future. Are the world’s polluters asking us to give up our language, our culture, and our national identity? We are not prepared to do that—we will stay and fight. If the water comes, it comes.”