A warming world will affect all corners of the globe, the UN warns
The risks facing people included losing access to drinking water, and rising sea levels, the study concluded.
The findings were published by the UN's Environment Programme (Unep).
Unep chief Achim Steiner said the report showed that time was running out for political leaders to reach a global agreement on curbing emissions.
Mr Steiner made his call for action at the launch of the UN Global Outlook for Ice and Snow report, which was being held in Tromso, Norway.
Norwegian Environment Minister
"The missing link is universal political action. Today's report should empower the public to take their leaders to task [and] should empower them to ask how much hotter it has to get before we act."
The study warns of a range of threats that could destabilise ecosystems around the world, with potentially devastating consequences for hundreds of millions of people.
Melting glaciers in Asia's mountains could affect an estimated 40% of the world's population, who rely on ice melt for crop irrigation and drinking water.
It added that rising temperatures were already resulting in the thawing of permafrost in places such as Siberia. This was leading to the release into the atmosphere of methane, a potent greenhouse gas.
The fate of the Antarctic and Greenland ice sheets, which hold almost all of the planet's freshwater ice, needed to be better understood, the UN publication urged.
It said that if emissions of greenhouse gases continued unabated, the massive ice sheets were likely to become unstable as the world continued to warm.
Without taking measures to mitigate sea level rise, an estimated 145 million people, primarily in Asia, would be exposed to the risk of flooding.
The UN said that the International Polar Year, a 24-month global scientific study of the polar regions, would help shed light on how climate change is altering the ice dynamics in these regions.
The authors also warned that less ice and snow cover was leading to more of the Sun's energy being absorbed by the land and the sea, rather than being reflected back into space.
They said this "positive feedback" could accelerate global warming and result in more abrupt shifts in the climate.
Norway's Environment Minister, Helen Bjoernoey, said the comprehensive study into the state of the world's snow and ice presented a bleak prognosis.
"To me, it is particularly alarming to realise climate change can be a reinforcing process - global warming results in further global warming," the minister observed.
"As documented in the report, melting of snow and ice will in itself have severe consequences on nature and society."