According to the World Meteorological Organization (WMO), were beaten in 2021 State of the Global Climate 2021 [PDF] four climate change records at once:
- Record high concentration of greenhouse gases: in 2020, their concentration reached 413.2 ppm (particles per million) and continues to grow: as of April 2022, it is 420.23 ppm. This is the highest value in the entire history of human existence, the last time global carbon dioxide levels consistently exceeded 400 ppm was about 4 million years ago, when the global temperature was about 3°C higher than today.
- Record ocean acidity: Probably, the pH of the surface of the open ocean is now the lowest in the last 26,000 years. A huge amount of anthropogenic carbon dioxide in the atmosphere is absorbed by the oceans. Emissions react with seawater, making it more acidic, threatening ecosystems and coasts. The decrease in ocean pH also shows that the seas are losing their ability to absorb CO2 from the atmosphere.
- Record high sea level: The average global sea level rose by an average of 4.5 millimeters per year between 2013 and 2021 — twice as much as between 1993 and 2002. This is bad news for coastal communities, which have also become more vulnerable to tropical cyclones.
- Record ocean temperature: The top 2,000 meters of ocean water have warmed significantly over the past two decades, and temperatures are expected to continue to warm in the future. Also, heat now penetrates to deeper levels than before.
In addition to these four records, the report highlights a marked spike in extreme weather conditions, including extreme heat, floods, droughts and hurricanes, that occurred in 2021, resulting in catastrophic economic losses of billions of dollars and leading to problems with food, water and human safety in selected regions.
The WMO report also confirms that the last seven years have been the warmest on record, and the average global temperature in 2021 was about 1.11°C above pre-industrial levels.
Independent climate scientists, commenting on the report, called it "terrifying" and "gloomy", but not particularly surprising, given that alarm bells have been heard for several decades. Humanity needs to reduce carbon emissions by ending the use of fossil fuels and reducing deforestation. Otherwise, we can expect that we will feel the effects of climate change more and more often.