2023 Puts Paris Accord Temperature Target in Jeopardy with New Global Heat Record

It’s official: 2023 was the hottest year on record, according to the planet’s top five meteorological organizations, with the global average temperature coming in at just a hair under 1.5°C (2.7°F) above the pre-industrial average, beating the previous record holders of 2016 and 2020 by a wide margin. This development puts the 1.5°C lower limit set out in the 2015 Paris Agreement—along with the many other climate targets made by individual countries—in severe jeopardy.

Although each of their methodologies and datasets are collected and developed independently, the five major meteorological organizations—the EU’s Copernicus Climate Change Service (C3S), the UK’s Met Office, the National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization (WMO)—all agree that 2023 was the hottest year on record, handily beating 2016 and 2020, both now tied for the second-highest global average temperature on record, by nearly a full fifth of a degree Celsius (0.45°F), the largest year-over-year increase seen in the modern era.

According to the Copernicus CCS, the global average temperature in 2023 came in at 1.48°C (2.66°F) above the 1850-1900 pre-industrial average, and 0.6°C (°F) above the 1991-2020 average, far too close to the 1.5°C preferred limit set out in the Paris Climate Agreement for comfort; it was originally estimated that worldwide carbon emissions would need to be cut by 30 percent by 2030—a mere six years from now—to maintain this target.

For reference, the 2016/2020 record was 1.30°C (2.34°F) above the pre-industrial global average, according to Copernicus’ measurements.

Copernicus also noted that 2023 was “the first time on record that every day within a year has exceeded 1°C above the 1850-1900 pre-industrial level,” with nearly half of those days “more than 1.5°C warmer than the 1850-1900 level,” with “two days in November… for the first time, more than 2°C [3.6°F] warmer.”

Although the southern hemisphere is estimated to have seen 0.1°C (0.18°F) in cooling from the water blasted into the atmosphere by the January 2022 eruption of the Hunga Tonga–Hunga Haʻapai underwater volcano, 2023 bore witness to a steady parade of temperature records being broken via multiple heat wave events that occurred around the globe.

With a temperature boost from the onset of El Niño conditions in the equatorial Pacific, sea surface temperatures also saw record-high levels between April and December 2203, with marine heat waves being experienced around the globe, including events “in parts of the Mediterranean, Gulf of Mexico and the Caribbean, Indian Ocean and North Pacific, and much of the North Atlantic,” according to the Copernicus press release.

Additionally, the sea ice extent around Antarctica also saw record lows, with the ice’s summer retreat reaching its lowest point on record in February, reaching only 33 percent of its average extent for that time of year.

“The extremes we have observed over the last few months provide a dramatic testimony of how far we now are from the climate in which our civilisation developed,” remarked Carlo Buontempo, the Director of the Copernicus Climate Change Service. “This has profound consequences for the Paris Agreement and all human endeavours. If we want to successfully manage our climate risk portfolio, we need to urgently decarbonise our economy whilst using climate data and knowledge to prepare for the future.”

Last year’s temperature extremes were severe enough for all five of the aforementioned climate service organizations to predict in September 2023 that that year would be a global record-breaker; the following November renowned climatologist and climate activist Dr. James Hansen warned that the pace of global warming was accelerating, declaring that “the 1.5-degree limit is deader than a doornail,” and that the Paris Agreement’s long-term “two-degree limit can be rescued, only with the help of purposeful actions,” such as CO2 emission reductions and large-scale carbon capture efforts.

“Humanity’s actions are scorching the earth. 2023 was a mere preview of the catastrophic future that awaits if we don’t act now,” warned UN Secretary-General António Guterres in a WMO press release. “We must respond to record-breaking temperature rises with path-breaking action.”

“We can still avoid the worst of climate catastrophe,” Guterres continued. “But only if we act now with the ambition required to limit the rise in global temperature to 1.5 degrees Celsius and deliver climate justice.”