An apparent hiatus in global warming?

Abstract Global warming first became evident beyond the bounds of natural variability in the 1970s, but increases in global mean surface temperatures have stalled in the 2000s. Increases in atmospheric greenhouse gases, notably carbon dioxide, create an energy imbalance at the top‐of‐atmosphere ( TOA ) even as the planet warms to adjust to this imbalance, which is estimated to be 0.5–1 W m −2 over the 2000s. Annual global fluctuations in TOA energy of up to 0.2 W m −2 occur from natural variations in clouds, aerosols, and changes in the Sun. At times of major volcanic eruptions the effects can be much larger. Yet global mean surface temperatures fluctuate much more than these can account for. An energy…

• NS
  National Science Foundation
• NA
  National Aeronautics and Space Administration

  Award: NNX09AH89G
• NC
  National Center for Atmospheric Research