Rising Sea Levels Pose Threat to Coastal Cities, Scientists Warn Recent studies reveal that global sea levels are rising faster than previously anticipated, placing millions of people in coastal cities at risk. Experts attribute this acceleration to the melting of polar ice caps and thermal expansion caused by global warming. According to a report published by the Intergovernmental Panel on Climate Change (IPCC), sea levels have risen by an average of 3.3 millimeters per year over the past t...