To Study Earth’s Climate, Look to the Ocean

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Human activities have released excess carbon dioxide and other greenhouse gases into the atmosphere, trapping extra heat in Earth’s climate system, commonly referred to as “global warming.” Decision makers, scientists, and the public are all interested in finding the best data to track this phenomenon and its influence on the environment.

To that end, a new paper published in the American Geophysical Union’s Eos, Earth and Space Science News, suggests that ocean heat content and sea level may provide a clearer view of how our planet is warming. According to the authors of “Taking the Pulse of the Planet,” ocean heating and sea level rise—which are measured independently—provide a clearer measure of heat accumulating in Earth’s system than does global average surface temperature.

Since shorter-term, natural temperature fluctuations have less influence on the ocean than on the atmosphere, scientists can more easily identify the signal of long-term global warming in the ocean. Because more than 90 percent of the excess heat in Earth’s system ends up in the ocean, monitoring the ocean is critical to measuring overall global warming.

“Monitoring the past and current climate helps us better understand climate change and enables future climate projections,” the authors conclude. “We must maintain and extend the existing global climate observing systems … as well as develop improved coupled (ocean–atmosphere) climate assessment and prediction tools to ensure reliable and continuous monitoring for Earth’s energy imbalance, ocean heat content, and sea level rise.”

International Contribution to Study

An international team of scientists contributed to the Eos paper. Along with NCEI, institutions represented by the authors include:

• The International Center for Climate and Environment Sciences, Beijing, China
• The National Center for Atmospheric Research, Boulder, Colorado
• The University of St. Thomas, St. Paul, Minnesota
• Mercator Océan, Brest, France

NCEI hosts and provides public access to atmospheric and ocean data. NCEI’s significant holdings encompass weather and climate data, the Global Temperature-Salinity Profile Program, the World Ocean Database, the Extended Reconstructed Sea Surface Temperature (ERSST) dataset, and the Global Argo Data Repository of ocean temperatures. NCEI also reports monthly on both global land and sea surface temperatures in our Global Climate Reports.