The Global warming caused by humans from burning of fossil fuels, land clearing, agriculture, and other human activities are melting polar ice caps and causing severe storms which causes high water levels and displacements of sand on beaches.
The increased volumes of carbon dioxide and other greenhouse gases released by the burning of fossil fuels, land clearing, agriculture, and other human activities have gradually increase the average temperature of the Earth's atmosphere and its oceans which causes the rising of sea level because of melting ice caps. It also increases the severity of storms. The rising of sea level and strong storms, causes the beaches to shrink because the water is pulling back all the sand.
A solution could be that people would take care of the earth better by not burning fossil fuels and releasing gases to the atmosphere. Another solution is that countries should have a law that is mandatory to use renewable energy so that we won't be using fuels that release gases to the atmosphere.