Published date November 1, 2018

Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition

  • Provides an independent estimate by using measurements of atmospheric oxygen (O2) and carbon dioxide (CO2)—levels of which increase as the ocean warms and releases gases—as a whole-ocean thermometer
  • Shows that the ocean gained 1.33±0.20×10^22 joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.83± 0.11 watts per square metre of Earth’s surface
  • Finds the ocean-warming effect that led to the outgassing of O2 and CO2 can be isolated from the direct effects of anthropogenic emissions and CO2 sinks
  • The results—which rely on high-precision O2 measurements dating back to 1991—suggest that ocean warming is at the high end of previous estimates, with implications for policy-relevant measurements of the Earth response to climate change, such as climate sensitivity to greenhouse gases and the thermal component of sea-level rise