The recent scientific projections indicate a concerning rise in global temperatures, signalling a grim reality that we are on the precipice of a significant environmental turning point. With the probability now at 66%, we are expected to cross the 1.5C global warming threshold between 2027, primarily driven by unabated human-induced emissions and the anticipated El Niño weather pattern.
Heralded as a symbol of global climate change negotiations, the 1.5C figure holds considerable importance. The 2015 Paris Agreement called upon countries to “pursue efforts” to limit global temperature rises to this level. A breach of this threshold, even temporarily, suggests an acceleration in the warming trend, an alarming signal for the health of our planet.
The 1.5C limit indicates a warming of 1.5C compared to temperatures recorded in the second half of the 19th Century, a period before industrialization-led fossil fuel emissions escalated significantly. Transgressing this threshold yearly for a decade or two would result in pronounced impacts of warming, including longer heatwaves, more intense storms, and rampant wildfires.
However, scientists emphasize that a one-time breach does not violate the Paris Agreement. There remains an opportunity to mitigate global warming through aggressive emissions reduction. The World Meteorological Organisation (WMO) has been tracking the odds of surpassing the 1.5C limit annually since 2020. The odds stood at less than 20% for the next five years. By the following year, it had escalated to 50%, and now, it stands at a worrying 66%.
To comprehend the gravity of surpassing 1.5C, one needs to understand that this figure is not a direct measure of global temperature but an indicator of Earth’s warming or cooling compared to the long-term global average. Scientists utilize average temperature data from 1850-1900 as a baseline to gauge the world’s temperature prior to our reliance on fossil fuels. Until 2018, a 2C warming was believed to be the threshold for significant impacts. However, recent estimates suggest that even a rise past 1.5C could have devastating consequences for our world.
As per researchers, there’s a 98% chance that the record global temperature of 1.28C above the pre-industrial figure, set in 2016, will be shattered before 2027. The head of long-range forecasts at the Met Office, Prof. Adam Scaife, notes that this is the first time in human history that we’ve been this close to exceeding 1.5C for the annual mean temperature.
Despite the alarming data, scientists highlight that temperatures must remain at or above 1.5C for 20 years before we can definitively claim the Paris Agreement threshold has been passed. The WMO Secretary-General, Prof. Petteri Taalas, reiterates that breaching the 1.5C limit temporarily is becoming increasingly probable.
Furthermore, the potential impact of the El Niño phenomenon raises the stakes even higher. The current La Niña event has partially offset climate warming for the past three years. However, the subsequent El Niño, projected to cause significant warming, might elevate global temperatures to a new high next year, though the exact magnitude of this event remains uncertain.
Regarding regional implications, the Arctic is expected to witness more significant warming than other regions, with temperature anomalies expected to be three times as large as the global figure over the next five northern hemisphere winters. Northern Europe, including the UK, will likely see increased rainfall from May to September in five years.
The trajectory of these projections underscores the urgent need for comprehensive climate action to steer our planet away from this dangerous precipice.