As global leaders gear up to meet at next week’s United Nations Climate Summit in New York, the president of a small Pacific island nation vulnerable to rising seas caused by global warming said the future of his people depends on creating a carbon-free world by 2050. “Out here in the middle of the Pacific Ocean, climate change has arrived,” Marshall Islands President Christopher Loeak said in a video address to his fellow heads of state. “Our atoll nation stands at the front line in the battle against climate change.” In the video, Loeak stands in front of a sea wall he built to protect his home and family from rising seas which have already engulfed several of the nation’s atolls — making them disappear forever. In order to avoid the worst effects of climate change, Loeak said, the world must embrace a carbon-free vision by the middle of the century. “Without it, no sea wall will be high enough to save my country,” Loeak said. At the U.N. summit on Tuesday, leaders will announce their plans to tackle climate change. It will be the last chance to confirm carbon cuts before a global climate treaty is signed in Paris at the end of 2015. “Paris cannot be another Copenhagen. The world has changed too much. The science is more alarming, the impacts more severe, the economics more compelling, and the politics more potent,” Loeak continued. It’s been nearly five years since world leaders last met to negotiate action to slow the effects of climate change, with few tangible results. Since that meeting in Copenhagen, a series of scientific reports has confirmed increasingly severe impacts if global warming is left unchecked.

The Intergovernmental Panel on Climate Change released a report in March saying that the effects of climate change were "worse than we had predicted" — a common trope in a series of reports on the effects of global warming released in past months. Sea levels are expected to rise by at least seven feet by the end of the century, said NASA and University of California researchers after discovering that a massive ice sheet in Western Antarctica was melting at an "unstoppable" rate. Other reports have detailed how global warming is making storms stronger and more frequent. The U.N. recently released a faux weather report for 2050 that showed daily highs of over 120 degrees Fahrenheit in much of the United States. While many low-lying areas such as parts of Florida will be under water due to rising seas by mid-century, other regions will suffer from extreme drought beyond the level of emergencies seen in recent years in states like California.

A clarion call