2017 the warmest year on record for the global ocean
January 28, 2018
A research team at the International Center for Climate and Environment Sciences at the Chinese Academy of Sciences in Beijing has published a study showing that 2017 was the warmest year on record for the global ocean.
The following is an extract from the paper by Lijing Cheng and Jiang Zhu
The oceans in the upper 2000 m were 1.51 × 1022 J warmer than the second warmest year of 2015 and 19.19×1022 J above the 1981–2010 climatological reference period (Fig. 1). For comparison, total electricity generation in China in 2016 was 0.00216 × 1022 J, which is 699 times smaller than the increase in ocean heat in 2017.
The long-term warming trend driven by human activities continued unabated. The high ocean temperatures in recent years have occurred as greenhouse gas levels in the atmosphere have also risen, reaching record highs in 2017. The results support the provisional announcement by the World Meteorological Organization in November 2017 that “Global ocean heat content in 2017 to date has been at or near record high levels”.
Owing to its large heat capacity, the ocean accumulates the warming derived from human activities; indeed, more than 90% of Earth’s residual heat related to global warming is absorbed by the ocean. As such, the global ocean heat content record robustly represents the signature of global warming and is impacted less by weather-related noise and climate variability such as El Nino and La Nina events. The year ˜ 2016 was cooler than both 2015 and 2017 owing to the huge El Nino, which took some of the heat out of the ocean. Ac- ˜ cording to the IAP ocean analysis, the last five years have been the five warmest years in the ocean. Measurements of ocean heating are a more reliable indicator than atmospheric measurements for tracking the vital signs of the health of the planet.