Changing sea levels have happened before and will happen again in a dynamic world. Newly detected rising sea levels in parts of the Indian Ocean, including the coastlines of the Bay of Bengal, the Arabian Sea, Sri Lanka, Sumatra and Java, appear to be at least partly a result of human induced increases of atmospheric greenhouse gases, says a study led by the University of Colorado at Boulder. The study, which combined sea surface measurements going back to the 1960s and satellite observations, will threaten inhabitants of some coastal areas and islands.