UN speaks of ‘catastrophe’ after climate indicators hit records

Greenhouse gas concentrations, sea level rise, ocean heat content and ocean acidification “record unprecedented values” in 2021

Four key indicators of climate change set records in 2021, the UN said, warning that the world’s energy system is leading humanity towards catastrophe.

Greenhouse gas concentrations, sea level rise, ocean heat content and ocean acidification “all registered unprecedented levels” last year, the World Meteorological Organization (WMO) said in its “State of the Climate” report. world in 2021”.

The document is a “gloomy confirmation of humanity’s failure to tackle climate disruption,” said UN Secretary-General Antonio Guterres.

Guterres warned that the world is moving ever closer to a “climate catastrophe” due to a “world energy system” that is broken. He called for urgent measures to be taken for a transition to renewable energywhich is “easy to achieve” and allows moving away from the “dead end” that fossil fuels represent.

The WMO declared that human activity has brought about changes on a planetary scale: on land, in the ocean and in the atmosphere, with harmful and lasting ramifications for ecosystems.

At a press conference, WMO Secretary General Petteri Taalas highlighted that the war in Ukraine has overshadowed climate change, which “remains humanity’s greatest challenge”.

heat record

The report confirms that the last seven years were the warmest in history, according to available records.

Weather phenomena linked to La Niña in early and late 2021 had an effect on cooling the planet’s temperatures over the past year. But despite that, 2021 was one of the hottest years on record, with an average world temperature nearly 1.11 degrees Celsius above pre-industrial levels.

The Paris Agreement aims to limit global temperature rise to +1.5°C compared to the pre-industrial era.

“We are now heading for a warming of 2.5 to 3 degrees, instead of 1.5,” Taalas said.

“The heat trapped in the atmosphere by human-made greenhouse gases will warm the planet for many generations to come. Sea level rise, ocean acidification and the increase in their heat content will continue for centuries unless mechanisms are invented to remove carbon from the atmosphere,” he added.

Heating

Among the four “crucial messages” in terms of indicators is the number of greenhouse gas concentrations, which reached a new world record in 2020, with 413.2 parts of carbon dioxide (CO2) per million (ppm) worldwide. , that is, 149% more than the pre-industrial level.

Data indicate that the rise continued into 2021 and early 2022, with an average monthly CO2 concentration at Mona Loa, Hawaii, reaching 416.45 ppm in April 2020, 419.05 ppm in April 2021, and 420 ppm. .23 ppm in April 2022.

The world-wide mean sea level reached a new maximum in 2021, after rising by an average of 4.5 millimeters per year during the period 2013-2021.

“This number, which is more than double that recorded between 1993 and 2002, is mainly due to a faster mass loss from the ice sheets”, the document indicates.

Ocean temperatures also hit a record high last year, and the heat “is penetrating deeper and deeper areas.” “The upper layer of the oceans, up to 2,000 meters deep, continued to warm in 2021 and everything indicates that this will continue in the future, an irreversible change in time scales of hundreds to thousands of years”, said the WMO.

The oceans absorb almost 23% of the annual human-made emissions of CO2 that accumulate in the atmosphere. While this slows the rise in atmospheric concentrations of CO2, it reacts with seawater and leads to ocean acidification.

During this period, the report indicates that the hole in the ozone layer over Antarctica was “wide and deep”, peaking at 24.8 million km2, a surface equivalent to the size of Africa.

António Guterres proposed five actions to stimulate the transition to renewable energy, including encouraging greater access to renewable energy technologies and materials, tripling private and public investment in renewable energy, and ending subsidies to fossil fuels.

Source: AFP