A Survey by the World Meteorological Organization (WMO) showed four key points of climate change that led to record-breaking 2021.

According to the WMO, concentrations of greenhouse gases, rising sea levels, ocean heat and ocean acidification are signs that human activities are causing changes in the planetary scale on earth, ocean and atmosphere, with harmful and lasting ramifications for sustainable development and ecosystems.

The organization's report pointed out that the last seven years have been the warmest on record -- and despite the temporary cooling, due to the cooling of La Niña conditions at the beginning and end of the year, this was not enough to reverse the rise in temperatures.

For example, the global average temperature in 2021 was about 1.1°C (± 0.13°C) above the pre-industrial level.

United Nations Secretary-General António Guterres used the publication of the WMO report to criticize "humanity's failure to combat the climate crisis," and to call for urgent action on fossil fuel issues.

Guterrez proposed five key actions to begin the renewable energy transition. They include increased access to renewable energy technology and supplies, private and public investments in renewables, and the end of fossil fuel subsidies totaling about $11 million per minute.

"Renewable [energies] are the only way to real energy security, stable energy prices and sustainable employment opportunities. If we act together, the transformation of renewable energy can be the peace project of the 21st century," he said.

Key indicators

According to the document, 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, or 149% of the pre-industrial level.

In specific locations, data show that gases increased in 2021 and early 2022.

Between 2015 and 2021, the heat of the ocean was record. The upper depth of 2000 meters of the ocean continued to warm in 2021 and is expected to continue warming in the future – an irreversible change in the centenary to millennial time scales.

The survey indicated that all data sets agree that ocean warming rates point to a particularly strong increase over the past two decades.

"The heat is penetrating deeper and deeper levels. Much of the ocean experienced at least one 'strong' marine heat wave sometime in 2021," they wrote.

With regard to ocean acidification, it is important to know that the ocean absorbs about 23% of the annual anthropogenic CO2 emissions into the atmosphere. This, according to the study, reacts with seawater and leads to ocean acidification, which threatens ecosystem organisms and services and, consequently, food security, tourism and coastal protection.

"As the pH [acidity] of the ocean decreases, its ability to absorb CO2 from the atmosphere also decreases," they said.

The research also found that although the year between 2020-2021 saw less melting than in recent years, there is a trend towards an acceleration of mass loss on multi-decadal time scales.

The researchers wrote that, on average, the world's reference glaciers have decreased by 33.5 meters (equivalent to ice) since 1950, with 76% of this thinning since 1980.]

The global average sea level reached a new record in 2021, after increasing by an average of 4.5 mm per year in the period 2013-2021. That's more than double the rate between 1993 and 2002 and is mainly due to the accelerated loss of ice mass from ice sheets, according to the report.

This has major implications for hundreds of millions of coastal inhabitants and increases vulnerability to tropical cyclones.

2021 was particularly punitive for glaciers in Canada and the U.S. Northwest with record loss of ice mass as a result of heatwaves and fires in June and July.

Greenland experienced an exceptional melting event in mid-August and the first rain recorded at Summit Station, the highest point of the ice sheet at an altitude of 3,216 meters.

Heat waves

Heatwaves have broken records in western North America and the Mediterranean. In Death Valley, California, thermometers reached 54.4°C on July 9, 2021, equaling a similar figure in 2020 as the highest recorded in the world since at least the 1930s, and Syracuse in Sicily reached 48.8°C.

The Canadian province of British Columbia reached 49.6 °C on June 29, and this contributed to more than 500 heat-related deaths. In addition to expanding forest fires that, in turn, worsened the impacts of floods in November.

"It's only a matter of time before we see another hottest year on record," said WMO Secretary General Professor Petteri Taalas.

According to the research, rising temperatures increase the risk of irreversible loss of marine and coastal ecosystems, including seagrass grass and algae forest. Coral reefs are especially vulnerable to climate change.

It is estimated that they will lose between 70% and 90% of their coverage area before 1.5 °C of heating and more than 99% if the average temperature increases 2°C.

Guterres said the world should act this decade to prevent worsening climate impacts and to keep the temperature rise below 1.5°C.

Source: CNN Brasil