Saving the world's glaciers is effectively a lost cause as they continue to melt at a surprising speed, with climate change indicators once again hitting record highs and global warming still soaring, the United Nations reported.

The last eight years have been the warmest ever recorded, while concentrations of greenhouse gases such as carbon dioxide hit new peaks, the U.N.'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 said 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 annual rate between 1993 and 2002.

Record high temperatures were also recorded in the oceans – where around 90% 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 1.5 degrees Celsius (2.7 degrees Fahrenheit) if possible.

The global mean temperature in 2022 was 1.15 degrees Celsius 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 highs in 2021.

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

Data indicate they continued to increase in 2022.

Glacier game lost

WMO chief Petteri Taalas told a press conference that extreme weather caused by greenhouse gas emissions "may continue until the 2060s, independent of our success in climate mitigation."

"We have already emitted so much, especially carbon dioxide, in the atmosphere that this kind of phasing out of the negative trend takes several decades."

The world's 40-odd reference glaciers – those for which long-term observations exist – saw an average thickness loss of more than 1.3 meters between October 2021 and October 2022 – much more significant than the average over the last decade.

The cumulative thickness loss since 1970 amounts to almost 30 meters.

In Europe, the Alps smashed records for glacier melt due to little winter snow, an intrusion of Saharan dust in March 2022 and heatwaves between May and early September.

"We have already lost the melting of the glaciers game because we already have such a high concentration of carbon dioxide," Taalas told Agence France-Presse (AFP).

In the Swiss Alps, "last summer we lost 6.2% of the glacier mass, which is the highest amount since records started."

"This is serious," he said, explaining that the disappearance of the glaciers would limit freshwater supplies for humans and agriculture and harm transport links if rivers become less navigable, calling it "a big risk for the future."

"Many of these mountain glaciers will disappear, and also the shrinking of the Antarctic and Greenland glaciers will continue for a long-term basis – unless we create a means to remove carbon dioxide from the atmosphere," he said.

Glimmers of hope

Despite the report's awful news, Taalas said there was cause for some optimism.

He said the means to battle climate change were becoming more affordable, green energy becoming cheaper than fossil fuels, and the world was developing better mitigation methods.

The planet is no longer heading towards 3 to 5 degrees Celsius warming, as forecast in 2014, but was now on track for 2.5 to 3 degrees Celsius warming, he said.

"In the best case, we would still be able to reach 1.5 degrees Celsius warming, which would be best for the welfare of mankind, the biosphere and the global economy," the WMO secretary-general told AFP.

Taalas said 32 countries had reduced their emissions and their economies still grew.

"There is no more automatic link between economic growth and emissions growth," he said.

In stark contrast to the world leaders of 10 years ago, now "practically all of them are talking about climate change as a serious problem and countries have started acting," he said.