Four Major Climate Records Were Smashed In 2021, Reveals New Global Report


Tom Hale

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

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Carbon emissions.

"Our climate is changing before our eyes," said WMO Secretary-General Professor Petteri Taalas. Image credit: Leonid Sorokin/

Four key climate change records – greenhouse gas concentrations, sea-level rise, ocean heat, and ocean acidification – were broken in 2021, according to the latest State of the Global Climate report.

Clearly, the state of the global climate isn’t looking good. In fact, the new report from the World Meteorological Organization (WMO) may be one of the clearest and most concise displays of our planet’s troubles seen in some time. 


On top of these four big record breakers, the report highlights the significant uptick in extreme weather – including exceptional heatwaves, flooding, drought, and hurricanes – that occurred in 2021, resulting in billions of dollars of economic losses, increasing concerns over food and water security, and a deepening amount of human suffering.

“Extreme weather has the most immediate impact on our daily lives," Professor Petteri Taalas, WMO Secretary-General, said in a statement. "Years of investment in disaster preparedness means that we are better at saving lives, though economic losses are soaring. But much more needs to be done, as we are seeing with the drought emergency unfolding in the Horn of Africa, the recent deadly flooding in South Africa and the extreme heat in India and Pakistan."

The WMO report also confirmed that the past seven years have been the warmest seven years on record, with the average global temperature of 2021 being approximately 1.11°C above pre-industrial levels.

“It is just a matter of time before we see another warmest year on record. Our climate is changing before our eyes,” Professor Taalas said.


Here are a few of the key points and takeaways from the report: 

Record high greenhouse gas concentrations

Greenhouse gas concentrations are officially confirmed to have reached a new global high in 2020, with the concentration of carbon dioxide reaching 413.2 parts per million (ppm) globally. This figure then proceeded to go up over the course of the following two years, reaching 420.23 ppm in April 2022. 

This is the highest concentration of carbon dioxide in the atmosphere for the whole of human history; the last time global carbon dioxide levels were consistently above 400 ppm was around 4 million years ago, a period when the world was about 3°C (5.4°F) hotter and sea levels were much higher than today.


Record ocean acidification

The report says that it’s likely the open ocean surface pH is now the lowest it has been for at least 26,000 years. A huge amount of human-driven CO2 in the atmosphere is absorbed by the oceans. The emissions react with seawater, leading it to become more acidic, threatening ecosystems, coastal protection, and food security. The decrease in ocean pH also shows that the seas are losing their capacity to absorb CO2 from the atmosphere

Record high sea levels

The global mean sea level reached a new record high in 2021, rising an average of 4.5 millimeters per year over the period 2013 to 2021, double the rate between 1993 and 2002. This is bad news for coastal human settlements and increases vulnerability to tropical cyclones.


Record ocean heat

All the data suggests that the upper 2,000 meters (6,561 feet) of the ocean water has experienced a strong temperature increase in the past two decades and it is expected that it will continue to warm in the future. It’s also clear that the warmth is now penetrating to ever deeper levels than before.

So, where do we go from here? 

Independent climate scientists commenting on the report have described it as “terrifying” and “grim reading,” but also hardly surprising given that the alarm bells have been ringing for decades. Above all, the experts say it highlights the need to dramatically up our efforts to lower carbon emissions through promptly ending fossil fuel use and slashing deforestation. If not, we can expect to see the impacts of climate change hitting harder, sooner, and more often. 


“The WMO State of the Global Climate in 2021 report is a terrifying warning for human health and well-being. Without urgent action to lower carbon emissions, millions of people, in the not far distant future, will die, primarily from hunger and from fighting over limited resources, made scarcer by climate change,“ said Professor Colin Butler of the National Centre for Epidemiology and Population Health at the Australian National University.

“We have to make enormous progress towards net zero this decade if we are to have even a 50 percent chance of limiting warming to 1.5°C. Net-zero by 2050 is too late to avoid 2°C warming with certainty," added Professor Pete Strutton from the Institute for Marine and Antarctic Studies at the University of Tasmania.


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