Observations of sea surface temperature [from the National Center for Environmental Prediction (top)], cloud ice [from Aura Microwave Limb Sounder (MLS, middle)], and upper tropospheric water vapor [from Aura MLS (bottom)] averaged for August 2004 through July 2005. These products illustrate increasing sea surface temperature associated with increasing convective clouds and increasing upper tropospheric water vapor. This convective cloud-induced moistening of the upper troposphere leads to an enhanced greenhouse effect due to water vapor—three times larger than without convection—exacerbating the impact of global warming. Credit: H. Su, California Institute of Technology/ Jet Propulsion Laboratory.