Sep 13, 2017

Taking the Pulse of the Planet

Lijing Cheng, Kevin E. Trenberth, John Fasullo, John Abraham, Tim P. Boyer, Karina von Schuckmann, and Jiang Zhu
  • States that decision-makers, scientists, and the general public want to know the rate at which Earth's system is accumulating heat and the amount by which it will warm in the future
  • Explores better ways of measuring global warming to answer these questions
  • States that global mean surface temperature (GMST), the most visible sign of a warming climate, relies on air temperature measurements that are influenced by:
    • Forcings that are external to the climate system (e.g., volcanic eruptions and aerosols and the 11-year sunspot cycle)
    • Internal fluctuations (weather phenomena, monsoons, El Niño/La Niña, and decadal cycles)
  • States that natural temperature variability is much more muted in the ocean than in the atmosphere, owing to the ocean’s greater ability to absorb heat (its heat capacity)
  • Compares the amplitude of the global warming signature (signal) to natural variability (noise) for GMST, OHC and SLR to define how well each metric tracks global warming
  • Finds that OHC and SLR are much better indicators of global warming than GMST