Humanity is heating the planet faster than ever before, a study has found.
Climate breakdown is occurring more rapidly with the heating rate almost doubling, according to research that excludes the effect of natural factors behind the latest scorching temperatures.
It found global heating accelerated from a steady rate of less than 0.2C per decade between 1970 and 2015 to about 0.35C per decade over the past 10 years. The rate is higher than scientists have seen since they started systematically taking the Earth’s temperature 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.
Extreme heat in recent years has been pushed higher by natural fluctuations – such as solar cycles, volcanic eruptions, and the weather pattern El Niño – that have led scientists to question whether startling temperature readings are outliers or the result of an increase in global heating.
The researchers applied a noise-reduction method to filter out the estimated effect of nonhuman factors in five major datasets that scientists have compiled to gauge the Earth’s temperature. In each of them, they found an acceleration in global heating emerged in 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.”
The blanket of carbon pollution smothering the Earth has heated the planet by about 1.4C since preindustrial levels, compounded by a recent drop in cooling sulphur pollutants that had provided temporary relief. A study Hausfather co-authored last year also found climate breakdown has speeded up, but had the rate slightly slower than the new study, at 0.27C a decade.
“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.”
The researchers said the acceleration fell within the scope of climate models. Based on temperatures from one of the datasets analysed, supplied by the EU’s Copernicus service, the world will cross the 1.5C threshold for long-term warming this year if the rate of warming does not slow. Analysis of the other four datasets showed a breach in 2028 or 2029.
Claudie Beaulieu, a climate scientist at the University of California Santa Cruz, said the findings imply that the window for limiting warming even to 2C above preindustrial levels would “narrow substantially” if faster warming persists.
“An important caveat, however, is that the acceleration may prove temporary,” said Beaulieu, who has published on the topic but was not involved in the new study. She added that the strong El Niño of 1998 also produced a period of apparent anomalous warming.
“The relative slowdown that followed was interpreted as evidence of a pause in global warming,” she said. “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.”
Climate scientists suspect global heating of 1.5C-2C may be enough to trigger near-apocalyptic “tipping points” that play out over decades and centuries, with the chances of catastrophe increasing at higher levels of warming. They are more confident about the damage climate breakdown will do in the short-term, such as making heatwaves hotter and allowing storms to unleash more rain.
The past three years have been the hottest three-year period on record, the World Meteorological Organization confirmed in January. Scientists have continued to log record-breaking levels of planet-heating pollution while raising fears that the planet’s carbon sinks – natural systems that remove CO2 from the atmosphere – may be starting to fail.
“How quickly the Earth continues to warm ultimately depends on how rapidly we reduce global CO2 emissions from fossil fuels to zero,” said Rahmstorf.
