NEW YORK: Earth’s warming rate reached an unprecedented high in 2023, with 92 percent of the last year’s record-shattering heat caused by humans, according to a group of 57 scientists using United Nations-approved methods.
Despite the faster warming rate, they found no significant acceleration in human-caused climate change beyond increased fossil fuel consumption. Last year’s extreme temperatures have sparked debate among scientists about whether climate change is accelerating or if other factors are involved.
Study lead author Piers Forster from Leeds University stated that the temperature rise is progressing as predicted, largely due to the buildup of carbon dioxide from fossil fuel use. Last year, the warming rate hit 0.26 degrees Celsius (0.47 degrees Fahrenheit) per decade, slightly higher than the previous year’s 0.25 degrees Celsius (0.45 degrees Fahrenheit) per decade. Although this increase is minor, it marks the highest rate ever recorded.
Outside experts emphasized the urgency of the situation. University of Wisconsin climate scientist Andrea Dutton, who was not part of the study, highlighted that addressing climate change is crucial to saving human lives. The team found that 2023 was 1.43 degrees Celsius warmer than the 1850-1900 average, with 1.31 degrees of that warming due to human activity. The remaining 8 percent was mostly attributed to El Niño and other natural factors.
Over a 10-year period, the world has warmed about 1.19 degrees Celsius (2.14 degrees Fahrenheit) since pre-industrial times. The report warned that if current fossil fuel use continues, Earth will likely exceed the 1.5 degrees Celsius warming threshold in approximately 4.5 years.
This projection aligns with earlier studies suggesting that we could be committed to this level of warming by early 2029 if emission trends remain unchanged. While surpassing the 1.5-degree limit would not spell the end of humanity, it would lead to severe impacts, including loss of coral reefs, Arctic sea ice, species, and more extreme weather events.
The unusual temperature rise in 2023, particularly in September, was within predicted ranges but at the high end. Co-author Sonia Seneviratne from ETH Zurich noted that while no global tipping point was reached, the current situation is already critical.
Other scientists, such as Jonathan Overpeck from the University of Michigan and Zeke Hausfather from Berkeley Earth, observed signs of acceleration, pointing out that the warming rate is now much higher than the 0.18 degrees Celsius (0.32 Fahrenheit) per decade recorded between 1970 and 2010.
The study found that the reduction in sulfur pollution from shipping, which had been cooling the atmosphere, was offset last year by carbon emissions from Canadian wildfires. Additionally, an undersea volcano that released heat-trapping water vapor also emitted cooling particles, balancing out the overall effect. Texas Tech climate scientist Katharine Hayhoe emphasized that the future climate trajectory is determined by human actions rather than physics alone.
