2023 recap: Significant climate milestones of the year Premium

2023 saw temperature records being broken month after month, and the year is all but set to be declared the hottest in history.

From registering the hottest summer on record to some significant steps at the yearly United Nations Climate Summit, 2023 was a year of climate extremes. The Hindu takes a look at some climate-related milestones that occurred during the course of the year.

2023 saw temperature records being broken month after month, and the year is all but set to be declared the hottest in history. According to Copernicus Climate Change Service (C3S), 2023 was 0.1°C warmer than the ten-month average for 2016, currently the warmest calendar year on record, and 1.43°C warmer than the pre-industrial reference period from January to October. In October 2023, average surface air temperature reached 15.30°C, 0.85°C above the 1991-2020 average for October.

“We can say with near certainty that 2023 will be the warmest year on record, and is currently 1.43°C above the preindustrial average,” said Samantha Burgess, C3S’s Deputy Director, in a statement in November.

Marine heat waves, which are periods of unusually warm ocean temperatures (warmer than 90% of the previous observations for a given time of year), were widespread in 2023. According to an analysis by the U.S. National Ocean and Atmospheric Administration (NOAA), 48% of global oceans saw marine heat waves in August 2023, which is an area larger than for any other month since the start of the record in 1991.

Global sea surface temperatures (SST) are usually at their highest in March. However, according to C3S data this year, global average SSTs remained at record high levels for the time of year throughout April, May, June, and July 2023, with the largest SST anomaly for any July on record.

“Over the long term, we’re seeing more heat and warmer sea surface temperatures pretty much everywhere. That long-term trend is almost entirely attributable to human forcing — the fact that we’ve put such a huge amount of greenhouse gas in the atmosphere since the start of the industrial era,” said Gavin Schmidt, the director of NASA’s Goddard Institute for Space Studies.

Sea ice extent is the area of ice that, in this case, covers the Antarctic Ocean at a given time. In 2023, Antarctic Sea ice maintained record low ice growth since April. According to NOAA, sea ice in the Antarctic reached an annual maximum extent of 16.96 million square km on September 10, 2023, setting a record low maximum in the satellite record that began in 1979. This year’s maximum is 1.03 million square km, below the previous record low set in 1986.