Earth's mean temperature has risen by 0.41 degrees Celsius from 1998 to 2021, which is one of the greatest temperature changes in recorded history.
The COP26 summit is a conference of parties held to help discuss and mitigate the climate change crisis. The topic of climate change has given rise to some misleading and false claims on social media. There have been reports by a few non-credible sources that claimed the Earth's temperature has not risen in the past 15 years. According to this claim, the highest recorded temperature on Earth was in 1998 and has not risen since. The claim also cited a leaked UN report that stated political heads worldwide raised their concerns about hidden data. However, the UN report data was taken out of context.
The United Nations report cited in these claims is compiled by Intergovernmental Panel on Climate Change (IPCC). The IPCC report stated that a gradual temperature rise was observed from 1998-2012. The temperature change was due to natural variability, volcanic eruptions, relatively low solar activity, and the average global surface warming rate.
The National Oceanic and Atmospheric Administration (NOAA) observed the change in temperature from 1998-2012. They reported that it was the warmest 15-year period on record at the time, but greenhouse gases continued to climb to new record highs. Other climate indicators continued to show the impacts of long-term, global-scale warming: subsurface ocean heating, global sea-level rise, the melting of glaciers and ice sheets, and record-low Arctic sea ice extent. The report also stated that the rate of surface warming since the late 1980s has been more than twice as fast as the warming averaged over the entire historical record.
NASA recorded a drastic increase in the Earth's temperature from 1988 to 2020. The Earth's mean temperature in 1998 was about 0.61 degrees Celsius higher than the mean temperature from 1951-1980. In 2020, it was 1.02 degrees Celsius higher.
In October 2021, BBC reported leaked documents from the U.N. compiled by IPCC. The report showed that some countries like Saudi Arabia, Japan, and Australia asked the U.N. to downplay the data of moving away from fossil fuels. The report also stated that some countries wanted to push back on U.N. goals closer to COP26.