Clouds – A Major Uncertainty
q How do all types of clouds (high and low
clouds) respond to global warming?
q Possibility 1: more clouds during global
warming
      Global warming
è More water vapor available to form clouds
è More clouds
q Possibility 2: less clouds during global
warming
      Global warming
è A warmer atmosphere can hold more water
vapor
è Reduce the condensation of water vapors
to clouds
è Less clouds