A new study says up to one-half of the world's sandy beaches could disappear by 2100 because of climate change.Australia, Canada, Chile, Mexico, China and the United States would be among the hardest hit, the research shows.The study was published in the journal Nature Climate Change.Michalis Vousdoukas was the lead investigator."Touristic areas which have sandy beaches as their main selling point will probably face strong consequences," he said.Aside from economic value, beaches play an important environmental role."Sandy beaches are important habitats supporting a wide range of species.They also protect the coast from the effects of storms, so without sandy beachesother inland environments can be affected by the effects of waves and saltwater intrusion," Vousdoukas added.Global sea levels have increased in recent decades.Major causes include melting glaciers and thermal expansion.Thermal expansion is the reaction of matter to increases in temperature.Water expands as it warms.Researchers examined satellite images showing shoreline changes during the past thirty years.They then used these trends in two different climate change situations.One situation predicted a small reduction in greenhouse gas emissions.The other situation predicted high greenhouse gas emissions.Greenhouse gas emissions have a link to climate change.By 2050, the researchers projected beach losses of between 13 and 15 percent.By 2100, the projected losses are from 35 to 49.5 percent, or 95,061 to 131,745 kilometers of beaches.Australia would lose more sandy shoreline than any other country,with 14,849 kilometers projected to be gone by 2100.Canada is second in projected losses.The United States could lose up to 5,530 kilometers.