Humanity Accelerates Planetary Heating
Human activity is causing the planet to warm at an unprecedented rate, according to a recent study. The research indicates that the pace of climate breakdown has nearly doubled, with global heating rising sharply after accounting for natural temperature fluctuations such as El Niño.
The study found that the rate of global warming increased from a steady pace of less than 0.2°C per decade between 1970 and 2015 to approximately 0.35°C per decade over the last ten years. This acceleration is the highest observed since systematic temperature records began in 1880.
“If the warming rate of the past 10 years continues, it would lead to a long-term exceedance of the 1.5C (2.7F) limit of the Paris agreement before 2030,” said Stefan Rahmstorf, a scientist at the Potsdam Institute for Climate Impact Research and co-author of the study.
Filtering Natural Variability
Recent extreme heat events have been influenced by natural factors such as solar cycles, volcanic eruptions, and the El Niño weather pattern. These elements have led some scientists to question whether recent high temperature readings are anomalies or indicative of an underlying increase in global warming.
To address this, the researchers employed a noise-reduction technique to remove the estimated effects of nonhuman factors from five major temperature datasets used to monitor Earth's climate. Each dataset revealed an acceleration in global warming beginning around 2013 or 2014.
“There is now pretty widespread – if not quite universal – agreement that there has been a detectable acceleration in warming in recent years,” said Zeke Hausfather, a climate scientist at Berkeley Earth who was not involved in the study. “However, it remains unclear how much of the additional warming over the past decade in particular is a forced response versus unforced variability.”
Carbon Pollution and Climate Trends
The accumulation of carbon pollution has increased global temperatures by about 1.4°C since preindustrial times. This warming has been intensified by a recent reduction in cooling sulphur pollutants, which had previously provided temporary mitigation. A study co-authored by Hausfather last year also identified an acceleration in climate breakdown, though it estimated a slightly lower warming rate of 0.27°C per decade compared to the new study.
“Either way, this represents a significant increase in the rate of warming,” said Hausfather. “[This] should be worrying as the world hurtles toward crossing 1.5C later this decade.”
Climate Models and Future Projections
The acceleration in warming aligns with projections from climate models. Using temperature data from the EU’s Copernicus service, one of the datasets analyzed, the study suggests the world could surpass the 1.5°C threshold for long-term warming as early as this year if the current rate of warming continues. The other four datasets project crossing this limit by 2028 or 2029.
Claudie Beaulieu, a climate scientist at the University of California Santa Cruz who was not involved in the study, noted that these findings imply a significantly reduced timeframe for limiting warming to 2°C above preindustrial levels if the accelerated warming persists.
“An important caveat, however, is that the acceleration may prove temporary,” said Beaulieu. She referenced the strong El Niño event of 1998, which also led to a period of apparent anomalous warming.
“The relative slowdown that followed was interpreted as evidence of a pause in global warming,” she added. “Continued monitoring over the next several years will be essential to determine whether the accelerated warming rate identified here represents a lasting shift or a transient feature of natural variability.”
Implications of Accelerated Warming
Climate scientists warn that global warming between 1.5°C and 2°C may trigger near-apocalyptic "tipping points" with consequences unfolding over decades and centuries. The likelihood of catastrophic outcomes increases with higher levels of warming. Scientists are more certain about the short-term impacts of climate breakdown, including intensified heatwaves and increased rainfall from storms.
The World Meteorological Organization reported in January that the past three years constitute the hottest three-year period on record. Concurrently, record-breaking levels of greenhouse gas emissions continue, while research indicates that natural carbon sinks, which absorb CO2 from the atmosphere, may be weakening.
“How quickly the Earth continues to warm ultimately depends on how rapidly we reduce global CO2 emissions from fossil fuels to zero,” said Rahmstorf.
