It is true that the UN sounded a "red alert," and world heat records were broken in 2023.
According to AP News and several other news sites, the UN's weather agency, the World Meteorological Organization (WMO), issued a "red alert" about global warming, citing "record-smashing increases" in greenhouse gases, land and water temperatures, and glacier and sea ice melting.
The Earth indeed goes through natural cycles of warming and cooling that change the climate and the weather. According to Climate.gov, "Earth has experienced cold periods (informally referred to as “ice ages,” or "glacials") and warm periods (“interglacials”) on roughly 100,000-year cycles for at least the last 1 million years."
However, human activity has pushed the greenhouse effect to new levels since the mid to late 19th century, dramatically altering the natural cycle and weather patterns. According to the National Resources Defense Council, the world is warmer than it has been at any other point in human history and getting warmer, with impacts that include extreme heat, protracted drought, increased flooding, more intense storms, and rising sea levels.
According to WMO, there is a "high probability" that 2024 will be another record-hot year.
https://apnews.com/article/wmo-un-climate-global-change-report-warming-2154285aabb0cf83dc9ca4015ea0016d
the WMO report: https://library.wmo.int/viewer/68835/download?file=1347_Statement_2023_en.pdf&type=pdf&navigator=1#:~:text=The%20World%20Meteorological%20Organization%20State,above%20the%201850–1900%20average.
https://www.climate.gov/news-features/climate-qa/hasnt-earth-warmed-and-cooled-naturally-throughout-history#:~:text=Yes.,the%20last%201%20million%20years.
https://www.nrdc.org/stories/what-are-causes-climate-change#natural
https://www.cnn.com/videos/world/2024/03/20/exp-world-climate-report-un-wmo-vause-hundal-intv-03201aseg1-cnni-world.cnn
https://www.usnews.com/news/world/articles/2024-03-19/un-sounds-red-alert-as-world-smashes-heat-records-in-2023