2021 was world’s 6th-warmest year on record | NOAA
According to an analysis by scientists at NOAA's National Centers for Environmental Information (NCEI),
2021 ranked sixth on the list of warmest years on record, dating back to 1880.
Earth’s average land and ocean surface temperature in 2021 was 1.51 degrees F (0.84 of a degree C) above the 20th-century average.
It also marked the 45th consecutive year (since 1977) with global temperatures rising above the 20th-century average. The years 2013-2021 all rank among the ten-warmest years on record.
The Northern Hemisphere’s land and ocean surface temperature was also sixth highest on record, at 1.96 degrees F (1.09 degrees C) above average. Looking at the Northern Hemisphere’s land areas only, the temperature was third warmest on record, behind 2016 (second warmest) and 2020 (the warmest).
Ocean heat content (OHC), which describes the amount of heat stored in the upper-levels of the ocean, was record high in 2021, surpassing the previous record high set in 2020. The seven highest OHCs have occurred in the last seven years (2015-2021). High ocean-heat content can contribute to sea-level rise.
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2021 Tied for 6th Warmest Year in Continued Trend, NASA Analysis Shows
Earth’s global average surface temperature in 2021 tied with 2018 as the sixth warmest on record, according to independent analyses done by NASA and the National Oceanic and Atmospheric Administration (NOAA).
Continuing the planet’s long-term warming trend, global temperatures in 2021 were 1.5 degrees Fahrenheit (0.85 degrees Celsius) above the average for NASA’s baseline period, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. NASA uses the period from 1951-1980 as a baseline to see how global temperature changes over time.
Collectively, the past eight years are the warmest years since modern recordkeeping began in 1880. This annual temperature data makes up the
global temperature record – which tells scientists the planet is warming.
According to NASA’s temperature record, Earth in 2021 was about 1.9 degrees Fahrenheit (or about 1.1 degrees Celsius) warmer than the late 19th century average, the start of the industrial revolution.
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Global Temperature Report for 2021 | Berkeley Earth
We conclude that 2021 was nominally the sixth warmest year on Earth since 1850. Our estimate of the global mean temperature in 2021 was significantly colder than 2020, but similar to 2018 and 2015. Given the uncertainties associated with temperature measurements, all three of these years 2015, 2018, and 2021 are essentially tied as the fifth, sixth, and seventh warmest years.
The last seven years have included all seven of the warmest years observed in the instrumental record.
Year-to-year rankings are likely to reflect short-term natural variability. In 2021, a persistent La Niña event is believed to have reduced temperatures somewhat compared to years without a La Niña event. Overall, the long-term trend remains consistent with an ongoing pattern of global warming.
While not a record warm year overall, 8.3% of the Earth’s surface did have a record warm annual average locally in 2021. By chance, these areas coincided with a number of major population centers. We estimate that ~1.8 billion people experienced a record high annual average in 2021, including most of the population of China.