Increasing Tropical Cyclone Precipitation due to Global Warming

While there is general consensus on the likely increase in global precipitation intensity under global warming and its underlying mechanism, it remains uncertain whether the same applies for extreme weather systems. Model predictions suggested that tropical cyclone precipitation intensity should increase in response to the rising sea surface temperature associated with global warming. However, no detailed study on this topic has been made using historical data. Here we present the results of an investigation on the influence of global warming on tropical cyclone precipitation intensity, which for the first time, provides observational evidence to such an issue. We define an index to estimate the potential variability of tropical cyclone precipitation intensity over the western North Pacific, and find that it has been on the increase at a rate of around +4% over the past two decades through the increase in atmospheric water vapor content under global warming. This suggest that even if TC frequency and intensity does not increase in the coming decades, the increase of atmospheric moisture will enhance the TC precipitation intensity, which will likely pose more severe threats and substantial losses over the tropics, particularly to coastal regions.