NBC News: “…Each January, the National Oceanic and Atmospheric Administration, NASA and the European Union Earth observation agency Copernicus publish reports on the previous year’s temperature data. Copernicus ranked 2021 as the fifth-hottest year since 1850, while NOAA and NASA ranked it as the sixth-hottest since 1880. An NBC News analysis of global weather stations with data going back for at least 30 years found that 691 weather stations out of 8,892 recorded their highest temperature ever in 2021. To distinguish unprecedented heat from everyday weather, scientists measure whether a region’s temperature during a particular time period is above or below the region’s historical temperature for the same time period. Friederike Otto, senior lecturer in climate science at the Grantham Institute for Climate Change and the Environment in London, said that measuring these temperature anomalies helps scientists tell the difference between day-to-day weather and longer-term climate changes. “It shows us the direct effects of global warming,” Otto said… In 2021, as Europe recorded its hottest summer, June’s weather anomalies in North America were so significant that the continent recorded its hottest June in 171 years, according to the January Copernicus report. The record-breaking heat was even more notable, scientists say, given that 2021 was a La Niña year, in which climate patterns in the Pacific Ocean produce cooler temperatures across the globe. An August 2021 United Nations International Panel on Climate Change report concluded that climate change caused by humans “is already affecting many weather and climate extremes in every region across the globe.” Otto, who helped write the report, said that last year’s weather events proved 2021 was “a year that made the evidence unavoidable.”…