2023 “smashed” the record for the hottest year by a huge margin, providing “dramatic testimony” of how much warmer and more dangerous today’s climate is from the cooler one in which human civilisation developed.
The planet was 1.48C hotter in 2023 compared with the period before the mass burning of fossil fuels ignited the climate crisis. The figure is very close to the 1.5C temperature target set by countries in Paris in 2015, although the global temperature would need to be consistently above 1.5C for the target to be considered broken.
Scientists at the EU’s Copernicus Climate Change Service (CCCS) said it was likely the 1.5C mark will be passed for the first time in the next 12 months.
The average temperature in 2023 was 0.17C higher than in 2016, the previous record year, marking a very large increase in climate terms. The primary cause of this increased global heating was continued record emissions of carbon dioxide, assisted by the return of the natural climate phenomenon El Niño.
The high temperatures drove heatwaves, floods and wildfires, damaging lives and livelihoods across the world. Analysis showed some extreme weather, such as heatwaves in Europe and the US, would have been virtually impossible without human-caused global heating.
The CCCS data also showed that 2023 was the first year on record when every day was at least 1C warmer than the 1850-1900 pre-industrial record. Almost half the days were 1.5C hotter and, for the first time, two days were more than 2C hotter. The higher temperatures increased from June, with September’s heat so far above previous averages that one scientist called it “gobsmackingly bananas”.
Carlo Buontempo, a CCCS director, said: “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.
“This has profound consequences for the Paris agreement and all human endeavours. If we want to successfully manage our climate risk, we need to urgently decarbonise our economy whilst using climate data and knowledge to prepare for the future.”
Scientists said recently that the Earth’s life support systems have been so damaged that the planet was “well outside the safe operating space for humanity”.
Samantha Burgess, the CCCS deputy director, said: “2023 was an exceptional year, with climate records tumbling like dominoes. Temperatures during 2023 likely exceed those of any period in at least the last 100,000 years.”
Prof Bill Collins, at the University of Reading, UK, said: “It is a shock that 2023 unarguably smashed the global temperature record. More global warming is expected to cause even wetter winters in the UK and yet more flooding.”
The CCCS highlighted a number of “remarkable” events in 2023, including huge blazes in Canada that helped drive up global carbon emissions from wildfires by 30%, and unprecedented ocean temperatures that caused marine heatwaves to strike many regions. Antarctic sea ice also crashed to record lows, having previously experienced little obvious impact from global heating.
Prof Brian Hoskins, at Imperial College London, said: “2023 has given us a taste of the climate extremes that occur near the Paris targets. It should shake the complacency displayed in the actions by most governments around the world.”
Prof Daniela Schmidt, at the University of Bristol, said: “The question is will this [record] lead to action and large scale changes in behaviour? Every little change now, reducing every increment of warming, is important, while too often ambitions of change are promised by 2050, in another generation.”
Prof John Marsham, at the University of Leeds, said: “We desperately need to rapidly cut fossil fuel use and reach net zero to preserve the livable climate that we all depend on.”
Hundreds of scientific studies have shown the climate crisis is causing more extreme and more frequent extreme weather. While 2023 was perceived by many as a year in which global heating accelerated, scientists said the higher temperatures were in line with the predicted result of increased carbon emissions. However, the speed and intensity of severe weather impacts alarmed many experts.
A separate analysis by Japan’s Meteorological Agency produced very similar results as Copernicus, with 2023 a record 1.43C above pre-industrial levels and beating the previous record by 0.14C.
Prof Andrew Dessler, at Texas A&M University in the US, said the record set in 2023 was not surprising: “Every year for the rest of your life will be one of the hottest [on] record. This in turn means that 2023 will end up being one of the coldest years of this century. Enjoy it while it lasts.”
