The year 2023 is officially the warmest on record—overtaking 2016, the previous warmest year, by an alarming margin. According to the latest data [13] from the European Union's Copernicus Climate Change Service [14], released Jan. 9, Earth was 1.48 degrees Celsius (2.66 Fahrenheit) hotter last year compared with pre-industrial levels—dangerously close to the 1.5-degree threshold set by the Paris climate deal [15]. 2023 also marked the first year in which each day was over one degree warmer than the pre-industrial average. Temperatures over 2023 likely exceeded those of any year over the past 100,000 years, the report found. This was partially due to the year's El Niño [16] climate phenomenon, but those impacts only began in June—and every subsequent month last year was the warmest on record for that particular month. September represented the largest climatological departure since record-keeping began over 170 years ago.
Extremely anomalous ocean heat content was also recorded last year. Normally, maximum ocean temperature is in March, at the end of the southern hemisphere summer. Instead, last year saw continued warming of the ocean surface from April right through to year's end, with record temperatures for all of those months. (PRI [18], PBS NewsHour [19], EuroNews [20], The Hill [21])
