Scientists from China, the USA, New Zealand, Italy, and France have together analysed annual temperature trends in the Earth’s ocean, revealing an alarming escalation of its range
The study, drawing data from the Institute of Atmospheric Physics (IAP) at the Chinese Academy of Sciences (CAS) and the National Centers for Environmental Information of the National Oceanic and Atmospheric Administration (NOAA), highlights the critical role the ocean plays in Earth’s climate system.
Ocean warming raises concerns
Over the past decade, each successive year has witnessed a rise in ocean temperatures, which is a significant threat to the planet’s delicate climate balance.
The ocean, covering 70% of the Earth, absorbs 90% of the heat generated by global warming. This influences the atmosphere, leading to fluctuating weather patterns and setting the pace of climate change.
The data from IAP and NOAA indicate substantial warming, with IAP reporting a 15 zettajoule increase in 2022, while NOAA records a slightly lower nine zettajoule.
Understanding the zettajoule impact
To fully grasp the significance of these numbers, it is important to note that the world consumes approximately 0.5 zettajoule of energy annually to power economies.
The energy increase reported by the IAP is equivalent to boiling away 2.3 billion Olympic-sized swimming pools. This highlights the challenge we face in tackling climate change.
Differences in data and the urgent need for clarity
The difference in reported ocean warming figures between IAP and NOAA has triggered questions about data accuracy. Scientists acknowledge that contrast come from differences in how each group handles data quality control and maps individual values onto a global grid. Dr Lijing Cheng, the study’s lead author, emphasises that the reported warming might be greater than the numbers suggest due to the variation in data handling.
Long-term trends and global consensus.
Graphs from IAP and NOAA datasets show a consensus on ocean warming since the late 1950s.
While specific years may differ, the overall trend remains consistent. The baseline, representing the average ocean temperature during 1981-2010, acts as a reference point for these comparisons, highlighting the reality of global warming’s impact on our oceans.
Ocean surface temperatures surge
Figures showing ocean surface temperatures reveal an unusual surge caused by long-term global warming and short-term fluctuations, such as El Niño in the Pacific Ocean.
Since May, a strong El Niño event has intensified ocean surface temperatures, changing global weather patterns. The substantial year-to-year natural variability makes ocean heat content (OHC) a crucial indicator of climate change.
Consequences for marine life and climate resilience
Changing rainfall and evaporation patterns alter ocean salinity, with salty areas becoming saltier and fresh areas fresher, impacting marine life and ocean currents.
The increase in stratification, where warm, less dense, and fresh waters near the surface slow the transfer of heat and carbon dioxide to deeper layers, is a severe threat to ocean plant and animal life.
Call for urgent action
The economic and human toll continues to rise as the ocean’s warming supercharges weather events, causing severe storms, heavy rain, and flooding.
Annual damages reach approximately $200 billion in the USA alone, emphasising the urgent need to transition away from fossil fuels. The study’s authors stress the importance of decarbonise the economy, adopting cleaner, renewable energy sources like wind, solar, and hydropower.
