In 2023, Earth experienced its hottest year on record, with the Copernicus Climate Change Service (C3S) reporting a surface temperature increase that nearly reached the critical threshold of 1.5 degrees Celsius.
Climate change exacerbated heatwaves, droughts, and wildfires globally, pushing the global thermometer 1.48 degrees Celsius above the preindustrial benchmark.
Samantha Burgess, deputy head of C3S, highlighted that 2023 marked the first year where all days surpassed one degree warmer than the pre-industrial period, and temperatures likely exceeded those of any period in the last 100,000 years.
Alarmingly, almost half of the year surpassed the 1.5-degree Celsius limit, a point at which climate impacts may become self-reinforcing and catastrophic. However, breaching the 1.5-degree threshold in 2024, as some scientists predict, does not necessarily signify a failure to meet the Paris Agreement target. The agreement allows for the possibility of reducing Earth's temperature after a period of "overshoot."
The year witnessed devastating events globally, including massive fires in Canada, extreme droughts in the Horn of Africa and the Middle East, unprecedented summer heatwaves in Europe, the United States, and China, along with record winter warmth in Australia and South America.
University of Reading climate change professor Ed Hawkins emphasised that these events will worsen until the world transitions away from fossil fuels and achieves net-zero emissions.
The Copernicus findings followed a climate agreement at COP28 in Dubai, calling for a gradual transition away from fossil fuels. Climate experts stressed the urgent need to rapidly cut fossil fuel use and achieve net zero to preserve a livable climate.
In 2023, another ominous record was set: two days in November exceeded the preindustrial benchmark by more than two degrees Celsius.
Copernicus predicts that the 12-month period ending in January or February 2024 will "exceed 1.5 degrees Celsius above the pre-industrial level."
The year also saw persistently high ocean temperatures globally, causing marine heatwaves and intensifying storms. Oceans, which absorb over 90 percent of excess heat from human activities, play a crucial role in regulating Earth's climate.
The concentrations of carbon dioxide and methane reached record levels in 2023, with 419 parts per million and 1,902 parts per billion, respectively.
Methane, the second-largest contributor to global warming after CO2, is responsible for around 30 percent of the rise in global temperatures since the industrial revolution, according to the United Nations Environment Programme (UNEP).