2023 was hottest year ever: What factors led to this?
2023 went down in history as the hottest year ever recorded. Earth's average temperature reached 1.48 degrees Celsius above the preindustrial average, according to the Copernicus Climate Change Service. This shatters the previous global temperature record by almost two-tenths of a degree, marking the largest jump ever observed. The announcement comes as no surprise to scientists who have witnessed the past year's extreme weather events, including raging wildfires, deadly ocean heatwaves, and catastrophic flooding.
Factors that contributed to the record heat
El Nino, a global climate pattern characterized by warm Pacific Ocean waters, played a significant role in boosting average planetary temperatures. Other factors include weakened westerly winds, reduced Saharan dust in the air, and a decline in sun-blocking aerosols due to efforts to reduce air pollution. Additionally, the massive underwater volcanic eruption of Hunga Tonga-Hunga Ha'apai in January 2022 released vast amounts of water vapor into the atmosphere, further trapping heat near the Earth's surface.
Oceans are important indicators of climate change
The Copernicus Climate Change Service also attributed this year's record-setting conditions partially to unprecedented warmth in the oceans' surface waters. Marine heat waves were observed from the Indian Ocean to the Gulf of Mexico, with parts of the Atlantic Ocean experiencing temperatures 4-5 degrees Celsius above average. Oceanographer Karina von Schuckmann said that the rapid warming of ocean water is a clear signal of Earth's energy imbalance, with heat building faster than it can be released from the planet.
Planet nears 1.5°C limit
The world is dangerously close to exceeding the climate goal of limiting the temperature increase to 1.5 degrees Celsius above preindustrial levels, as set in the Paris Climate Agreement. Copernicus director Carlo Buontempo cautioned that by January or February's end, the planet's yearly average temperature might breach this limit. While some climate science groups, like Berkeley Earth, suggest that the line has already been crossed, confirming this requires temperatures to persistently stay above the threshold for at least 20 years.
The road ahead
The year 2023 serves as a stark warning of what the future holds if urgent action is not taken. "As a society, we have to be better at using this knowledge because the future will not be like our past," Buontempo urged, emphasizing the imperative for collective action. Paulo Ceppi, a climate scientist at Imperial College London, stressed that reaching "net zero" greenhouse gas emissions is essential to reverse Earth's long-term warming trend.
