GENEVA (AFP) – Four key climate change indicators all set new record highs in 2021, the United Nations (UN) said yesterday, warning that the global energy system was driving humanity towards catastrophe.
Greenhouse gas concentrations, sea level rise, ocean heat and ocean acidification all set new records last year, the UN’s World Meteorological Organization (WMO) said in its State of the Global Climate in 2021 report.
The annual overview is “a dismal litany of humanity’s failure to tackle climate disruption”, UN Chief Antonio Guterres said.
“The global energy system is broken and bringing us ever closer to climate catastrophe.
“We must end fossil fuel pollution and accelerate the renewable energy transition before we incinerate our only home.”
The WMO said human activity was causing planetary-scale changes on land, in the ocean and in the atmosphere, with harmful and long-lasting ramifications for ecosystems. The report confirmed that the past seven years were the top hottest years on record.
Back-to-back La Nina events at the start and end of 2021 had a cooling effect on global temperatures last year. Even so, it was still one of the warmest years ever recorded, with the average global temperature in 2021 about 1.11 degrees Celsius above the pre-industrial level.
The 2015 Paris Agreement on climate change 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 if possible.
“Our climate is changing before our eyes,” said WMO Chief Petteri Taalas.
“The heat trapped by human-induced greenhouse gases will warm the planet for many generations to come. Sea level rise, ocean heat and acidification will continue for hundreds of years unless means to remove carbon from the atmosphere are invented.”
Four key indicators of climate change “build a consistent picture of a warming world that touches all parts of the Earth system”, the report said.
Greenhouse gas concentrations reached a new global high in 2020, when the concentration of carbon dioxide (CO2) reached 413.2 parts per million (ppm) globally.
Data indicate that they continued to increase in 2021 and early 2022, with monthly average CO2 at Mona Loa in Hawaii reaching 416.45 ppm in April 2020, 419.05 ppm in April 2021, and 420.23 ppm in April 2022, the report said. Global mean sea level reached a new record high in 2021, rising an average of 4.5 millimetres per year throughout 2013 to 2021.
