Many of the world's economies could shrink in the next few decades as climate change makes it harder to find fresh water supplies.

    The lack of water could spur waves of migration, spark conflicts within countries and cause food prices to spike to untenable levels, the World Bank warned in a report this week.

    Researchers found economies in Africa's central and Sahel regions, East Asia and the Middle East could see growth rates decline by up to 6% of gross domestic product (GDP) by 2050 due to water-related losses in agriculture, health, income and property. "Water scarcity is a major threat to economic growth and stability around the world, and climate change is making the problem worse," the World Bank's president Jim Yong Kim said in a statement. "If countries do not take action to better manage water resources, our analysis shows that some regions with large populations could be living with long periods of negative economic growth." Still, "countries can enact policies now that will help them manage water sustainability for the years ahead," he added. 

    Global temperatures are rising as greenhouse gas emissions soar, largely thanks to human activities such as burning fossil fuels for energy and clearcutting forests, scientists say.

    As the planet warms, droughts and extreme floods will become more frequent and intense, while snowfall will be replaced by rain, which evaporates faster. Shrinking mountain snow packs and melting inland glaciers will deplete fresh water resources, while rising sea levels will cause saltwater to taint the groundwater.