A recent social media post claimed that the 1930s were the hottest years on record, but this assertion has been debunked by multiple reputable sources. The World Meteorological Organisation (WMO) confirmed that 2010–2019 was the "warmest decade in history", with temperatures 1.1°C above pre-industrial levels. This finding has been echoed by various prominent organisations tracking global temperature.
According to the WMO's 2021 analysis, which incorporated additional data, 2010–2019 was indeed the hottest decade on record, confirming earlier findings. The National Aeronautics and Space Administration (NASA) also found in 2020 that the 2010s were "clearly the warmest decade on record". This consensus among leading organisations underscores the accuracy of the data.
Temperature data from four leading datasets align closely, clearly showing that 2010–2019 was hotter than any other decade on record, including the 1930s. Since the 1980s, each decade has been hotter than the last, the WMO found, a trend that continues today. This steady rise in temperatures highlights the ongoing impact of climate change.
The UN Intergovernmental Panel on Climate Change (IPCC) reported that global surface temperature from 2001–2020 was 0.99°C higher than in 1850–1900. The IPCC also stated that global surface temperature has increased faster since 1970 than in any other 50-year period over at least the last 2000 years. This significant increase in temperature has serious implications for the planet.
The 2010s' record as the hottest decade has even been confirmed by Guinness World Records. However, this record is expected to be broken soon, with 2023–2025 projected to be the hottest three years on record. Scientists have warned that 2026 is on track to be the hottest year ever recorded, even as the Northern Hemisphere experiences devastating heat waves.
PesaCheck, a public finance fact-checking initiative, has examined the claim that the 1930s was the hottest decade ever recorded and finds it to be FALSE. This fact-check was part of an ongoing series examining content marked as potential misinformation on Facebook and other social media platforms. PesaCheck aims to provide the public with deeper insight and context to posts they see in their social media feeds.
The fact-check was written by PesaCheck climate change fact-checker Christiaan van der Merwe and edited by PesaCheck chief copy editor Stephen Ndegwa. The article was approved for publication by PesaCheck’s managing editor Doreen Wainainah. PesaCheck was co-founded by Catherine Gicheru and Justin Arenstein, and is being incubated by the continent's largest civic technology organisation.
Key points
- The 2010s remain the hottest decade on record, with temperatures 1.1°C above pre-industrial levels.
- Multiple reputable sources, including the WMO and NASA, confirm that 2010–2019 was the hottest decade on record.
- The 2020s are projected to break the record, with 2023–2025 expected to be the hottest three years on record.
