The world's glaciers melted at dramatic speed last year and saving them is effectively a lost cause, the United Nations reported Friday, as climate change indicators once again hit record highs.

The last eight years have been the warmest ever recorded, while concentrations of greenhouse gases such as carbon dioxide hit new peaks, the UN's World Meteorological Organization said.

"Antarctic sea ice fell to its lowest extent on record and the melting of some European glaciers was, literally, off the charts," the WMO spelled out as it launched its annual climate overview.

Sea levels are also at a record high, having risen by an average of 4.62 millimeters per year between 2013 and 2022 -- double the rate it was between 1993 and 2002.

Record high temperatures were recorded in the oceans -- where around 90 percent of the heat trapped on Earth by greenhouse gases ends up.

The 2015 Paris Agreement saw countries agree to cap global warming at "well below" two degrees Celsius above average levels measured between 1850 and 1900 -- and 1.5C if possible.

The global mean temperature in 2022 was 1.15 C above the 1850-1900 average, the WMO report said.

Record global mean temperatures over the past eight years came despite the cooling impact of a drawn-out La Nina weather phenomenon that stretched over nearly half that period.

The report said greenhouse gas concentrations reached new global highs in 2021.

The concentration of carbon dioxide (CO2) reached 415.7 parts per million globally, or 149 percent of the pre-industrial (1750) level, while methane reached 262 percent and nitrous oxide hit 124 percent.

Data indicate they continued to increase in 2022.