Global Changes in Water Vapor 1979–2020

Global-scale changes in water vapor and responses to surface temperature variability since 1979 are evaluated across a range of satellite ground-based observations, reanalysis (ERA5) coupled atmosphere-only CMIP6 climate model simulations. Global-mean column integrated increased by 1%/decade during 1988-2014 observations However, simulations overestimate trends this is partly explained past studies showing that internal suppressed observed warming period. Decreases low-altitude tropical ERA5 before around 1993 considered suspect based on inconsistency with microwave data 1979. AIRS does not capture the tropospheric 2002 shown other satellite, products. global interannual consistent datasets increases ∼4-5% near 10-15% at 300 hPa for each 1°C increase temperature. Global thermodynamic amplification upper Clausius Clapeyron dependence saturation pressure dominated ocean responses. Upper moistening larger greater warming.