The world's glaciers melted at dramatic speed last year, with global sea levels rising at double the pace they did two decades ago, a UN climate report said on Friday, ahead of Earth Day.

The report, published by the UN's World Meteorological Organization (WMO), said the years between 2015-2022 were the warmest on record. The heatwave which struck Europe last summer caused more than 15,000 deaths.

The melting rate of some European glaciers was also "off the charts," according to the report, with some glaciers losing up to 1.3 meters (4.3 feet) of average thickness between October 2021 and October 2022.

"We have already lost this melting of glaciers game and sea level rise game so that's bad news," WMO Secretary-General Petteri Taalas told a press conference. This is due to the high level of greenhouse gases which have already been emitted, causing water to continue to rise for "thousands of years."

Record high temperatures

The La Nina cooling weather phenomenon failed to ease the temperature hikes, with the past eight years considered the highest mean temperatures on record.

In 2021, greenhouse gas concentrations peaked. Carbon dioxide (CO2) concentration was at 415.7 parts per million globally, which is 149% of the pre-industrial level. Methane meanwhile stood at 262% and nitrous oxide at 124%.

2022 data suggested they continued to increase.

Oceans were meanwhile the warmest on record. Some 58% of ocean surfaces experienced a marine heatwave, the WMO said.

"Around 90% of the energy trapped in the climate system by greenhouse gases goes into the ocean, somewhat ameliorating even higher temperature increases but posing risks to marine ecosystems," a summary of the report read.

Taalas predicted the extreme weather patterns to continue into the 2060s, even with successful mitigation steps, due to the damage already done. He said however that with enough effort, things could take a turn for the better afterwards.

"The good news would be that we would be able to phase out this negative trend and even reach the 1.5 degrees (Celsius) limit," he said.

rmt/wd (AFP, Reuters)