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Accelerated Rise in Sea Surface Temperatures Observed Over Four Decades
Recent satellite data reveals a concerning trend: sea-surface temperatures have been warming at an unprecedented rate over the last forty years. This trend underscores the growing urgency of addressing climate change as its impacts become increasingly evident.
Between the years 1985 and 1989, the observed rate of warming was approximately 0.06 degrees Celsius per decade. However, the period from 2019 to 2023 has seen this figure rise significantly, with temperatures increasing by an alarming 0.27 degrees Celsius per decade. This indicates that the rate of warming is now 4.5 times faster than it was towards the end of the 1980s.
The research, which calculated monthly global mean sea-surface temperatures, utilized extensive satellite data provided by the European Space Agency’s Climate Change Initiative (CCI). The dataset includes contributions from 20 infrared radiometers aboard multiple satellites, such as ESA’s ERS-1, ERS-2, Envisat, Copernicus Sentinel-3, along with two microwave radiometers spanning from 1980 to 2023. This comprehensive dataset allows for an accurate representation of global sea temperature trends.
Understanding the Causes of Rapid Warming
The significant rise in temperatures was highlighted in a study published in the journal Environmental Research Letters. Researchers have linked the rising sea-surface temperatures directly to increasing greenhouse gas concentrations in the atmosphere. According to Chris Merchant, the lead author from the University of Reading in the UK, the accumulation of greenhouse gases traps heat in the atmosphere, leading to a crucial energy imbalance between the solar energy absorbed by the Earth and the energy radiating back into space. This imbalance is a key driver of climate change. Merchant emphasized the importance of continuous monitoring and data enhancements to ensure that climate models accurately predict future temperature trajectories.
The study explored various influences contributing to ocean warming, including short-term phenomena like El Niño and volcanic eruptions. While these events can cause temporary fluctuations in sea temperature, the study concludes that they do not significantly disrupt the underlying long-term warming trend.
Co-author Owen Embury, who leads the scientific efforts for the ESA-CCI sea-surface temperature project, noted that their findings indicate that the relentless accumulation of planetary energy is the primary influence on long-term sea-surface warming. Although short-term variations such as those caused by El Niño, volcanic activity, and solar radiation changes introduce some variability, they do not detract from the overall acceleration observed.
Implications for Climate Research
The findings of this study will support the European Space Agency’s ongoing science exploitation initiative, MOTECUSOMA, which focuses on studying Earth’s energy imbalance and its ramifications for climate change. Embury articulated the challenges posed by increasing ocean heat, which sharpens the likelihood of extreme weather conditions, disrupts ecosystems, and exacerbates sea level rise. This reality highlights the necessity for precise climate projections and ongoing observational commitments.
For those interested in the data underpinning this research, the sea surface temperature records are accessible through the ESA CCI data portal. Moreover, formatted versions compatible with global climate modeling are available through the Obs4MIPs framework.
Source
www.esa.int