A sharp rise in global temperatures in 2023 has triggered a relentless series of disasters worldwide, including deadly wildfires in Los Angeles and flooding in Valencia. Scientists have rushed to uncover the causes of this anomaly and concluded that a significant warming of the Earth’s surface oceans played a crucial role. A new study from the University of Reading in the UK revealed that the upper layers of the oceans are now warming more than four times faster than they were in the late 1980s.
What did the researchers discover? Led by meteorologist Chris Merchant, the team proposed several theories to shed light on the excess heat that exceeded expected warming from El Niño and greenhouse gas emissions. Among these theories were: an increase in water vapor trapping heat due to the eruption of the Hunga Tonga-Hunga Ha’apai volcano in 2022; a reduction in the use of cooling aerosols (due to changes in shipping regulations); and peak activity in the current solar cycle. However, even collectively, these theories could not fully explain the observed temperature spike, as reported by Science Alert.
To further investigate, scientists utilized satellite data collected since 1985 to calculate the dynamics of ocean surface warming. The team found that 40 years ago, the rate of warming was about 0.06 °C, but it has now increased to 0.27 °C. They noted that this is not a linear increase in temperature, but rather an accelerating one. While part of the excess heat was indeed caused by the recent El Niño, researchers determined that 44 percent of the acceleration in ocean warming is due to the oceans absorbing heat significantly faster than predicted over the last decade. “If you imagine the oceans as a bathtub, in the 1980s the hot tap was running slowly, warming the water by just a fraction of a degree each decade. But now the hot tap is running much faster, and the warming is picking up speed,” said Chris Merchant.
Why is this trend alarming? The team of scientists argues that if this trend continues, the rise in ocean temperatures over the next 20 years will surpass the levels observed in the last 40 years. Meanwhile, global warming is wreaking havoc on wildlife, leaving millions without food due to failed crops, and undermining the health of the planet’s population.
According to Merchant’s team, policymakers and society must understand that the pace of global warming poses a threat of rapid and irreversible changes likely to occur in the coming decades. “This underscores the urgency of radically reducing fossil fuel consumption,” the team wrote in their report. They assert that every little action we can take to reduce greenhouse gas emissions will save future lives, regardless of where we stand on this dark timeline. The findings of the study were published in the journal Environmental Research Letters.