Britain and the United States launched on Monday a $25 million project, involving 100 scientists, to study the risks of a collapse of the giant Thwaites Glacier in Antarctica that is already shrinking and nudging up global sea levels. The glacier is roughly the size of Florida or Britain, in West Antarctica, the UK Natural Environment Research Council and US National Science Foundation said in a joint statement, as they announced the five-year research. Thwaites and the nearby Pine Island Glacier are two of the biggest and fastest-retreating glaciers in Antarctica. If both abruptly collapsed, allowing ice far inland to flow faster into the oceans, world sea levels could rise by more than a meter, threatening cities from Shanghai to San Francisco and low-lying coastal regions. “Rising sea levels are a globally important issue which cannot be tackled by one country alone," UK science minister Sam Gyimah said. The scientists would deploy planes, hot water drills, satellite measurements, ships and robot submarines to one of the remotest parts of the planet to see "whether the glaciers collapse could begin in the next few decades or centuries," the statement said. Despite satellites, "there are still many aspects of the ice and ocean that cannot be determined from space," said Ted Scambos, of the National Snow and Ice Data Center and the lead US scientific coordinator. Other scientists from South Korea, Germany, Sweden, New Zealand and Finland would also contribute.