A new study has found that more than half of the world’s lakes have shrunk since the 1990s. The study blames the shrinkage on the effects of climate change. The researchers said the finding intensifies concerns about world water supplies for drinking, agriculture and hydropower. An international team of scientists recently reported their results in the publication Science. The team reported some of the world's most important freshwater suppliers lost water at an estimated rate of 22 gigatons per year for nearly 30 years. This included the Caspian Sea between Europe and Asia and South America's Lake Titicaca in the Andes mountains.