The biggest losses are in Antarctica and Greenland, but many highly-populated lower latitude locations are experiencing significant water losses in areas that traditionally provide water supply, said the WMO.
The agency said there were major ramifications for water security, as only 0.5 per cent of water on Earth is useable and available fresh water.
"Increasing temperatures are resulting in global and regional precipitation changes, leading to shifts in rainfall patterns and agricultural seasons, with a major impact on food security and human health and well-being," said Taalas.
We cannot wait
Meanwhile water-related hazards have increased in frequency over the past 20 years.
Since 2000, flood-related disasters have risen by 134 per cent compared with the previous two decades.
"We have seven percent more humidity in the atmosphere because of the current warming and that's also contributing to the flooding," Taalas told a press conference.
Most of the flood-related deaths and economic losses were recorded in Asia, where river flood warning systems require strengthening, said the WMO.
At the same time, there has been around a 30 per cent increase in the amount and duration of drought events since 2000, with Africa the worst-affected continent.
Taalas urged countries at COP26 to raise their game.
He said most world leaders were talking about climate change as a major risk to the welfare of mankind, but their actions were not matching their words.
"We cannot wait for decades to start acting," he said.
"That's also a message for countries like China which has said that they would like to become carbon neutral by 2060 but they don't have a concrete plan for the coming decade."
He said the top priority at COP26 was stepping up ambition levels in climate mitigation, but more work was also needed on climate adaptations, as the negative trend in weather patterns will continue for the coming decades -- and the coming centuries when it comes to the melting of glaciers and sea levels rising.