Global warming has accelerated sharply since 2015, with the pace of temperature increase nearly doubling over the past decade. A new study suggests the 1.5°C threshold of the Paris Agreement could be crossed before 2030.
Global warming has intensified since 2015
The planet is warming at an unprecedented pace. A new study has found that global warming is accelerating rapidly, with the rate of temperature increase nearly doubling over the past decade.
Because of this human-driven acceleration, the 1.5°C threshold set by the Paris Agreement could be exceeded even before 2030, according to research published in the journal Geophysical Research Letters.
In recent years, exceptionally high global temperatures have fueled debate over whether global warming has entered a phase of acceleration. Many scientists suspected this trend was underway, but until now statistical evidence confirming the hypothesis had remained limited.
Previous analyses had suggested that the acceleration, meaning an increase in the warming rate, had not yet reached the 95% statistical confidence level because of the natural variability of global temperatures.
A decade of faster global warming
For several decades starting in the 1970s, global temperature increases were considered relatively steady. More recently, scientists began to question whether the pace of global warming had accelerated since then.
Determining this has been difficult because natural fluctuations can temporarily alter the rate of warming. Until now, no statistically significant evidence had demonstrated a clear acceleration.
The new study changes that picture by removing the estimated influence of three major sources of natural variability: El Niño events, volcanic activity and solar variations.
Once these factors were filtered out, the adjusted data revealed a clearer signal. The results show that global warming has accelerated with a probability exceeding 98%, indicating that warming over the past decade has been faster than during any previous ten-year period.
The warming rate has nearly doubled since 2015
After removing the estimated effects of El Niño, volcanic eruptions and solar variability, the global temperature curve becomes significantly less noisy.
This refined dataset shows that global warming began accelerating in a statistically significant way around 2015.
Researchers found that since the 1970s the world has warmed at an average rate of about 0.2°C per decade. Since 2015, however, that pace appears to have increased sharply, reaching approximately 0.35°C per decade.
The 1.5°C threshold could be crossed before 2030
A faster warming rate raises serious concerns and highlights how insufficient global efforts have been so far to slow global warming under the Paris Agreement.
If the current warming rate continues, the authors estimate that the 1.5°C threshold, defined as the limit of the Paris Agreement and calculated over a twenty-year average, could be exceeded between 2026 and 2029.
Under this scenario, avoiding a long-term temperature increase beyond 2°C would become significantly more difficult.
The full study is available in Geophysical Research Letters.
