Their protection is essential for countries to transition into resource-efficient and sustainable economies, the report -- The Economics of Ecosystems and Biodiversity -- said.
The report was produced by a U.N.-backed initiative that seeks to draw attention to the global economic benefits of biodiversity.
"Policies and decisions often do not take into account the many services that wetlands provide -- thus leading to the rapid degradation and loss of wetlands globally," Achim Steiner, executive director of the U.N. Environment Program, said in announcing the report.
Half of the world's wetlands were lost during the 20th century due to intensive agricultural production, unsustainable water extraction for domestic and industrial use, urbanization, infrastructure development and pollution, the UNEP said.
"There is an urgent need to put wetlands and water-related ecosystem services at the heart of water management in order to meet the social, economic and environmental needs of a global population predicted to reach 9 billion by 2050," Steiner said.