There is more proof that the Greenland and Antarctica ice sheets are melting and not growing, according to a scientist who called Monday for better models to follow and predict the process, according to dpa. Delivering a report at the annual American Association for the Advancement of Science meeting in Chicago, Richard Alley, a professor of geosciences at Penn State University in Pennsylvania predicted that sea levels would rise more than seven metres if the Greenland ice sheet melted. A total melt in Antarctica would add more than 60 metres of water to sea level. "We do not think that we will lose all, or even most, of Antarctica's ice sheet," said Alley. "But important losses may have already started and could raise sea level as much or more than melting of Greenland's ice over hundreds or thousands of years." Alley called for a better system of modelling to portray in greater detail the interaction of ice sheets, the atmosphere, oceans and clouds. He noted that the government and scientists partnered to create the atmospheric and ocean models, but collaborations to model the ice are only just being developed.