The reason for the smaller percentage increase in the RCM is the greater number of heavy events in the simulation of present climate. The change in extreme rainfall intensity is greater for events with longer return periods, implying even larger increases in the intensity of more-extreme events with return periods exceeding 20 years. Summary Increases in heavy rainfall intensity have occurred over the last century in Australia, Japan and the USA, during a period in which global mean temperatures have increased. Concentrations of carbon dioxide and other greenhouse gases are also increasing in the atmosphere. This is expected to lead to global warming and climate change.
Climate models can simulate future climate change due to increasing greenhouse gas concentrations.
A general increase in heavy rainfall intensity is simulated by coarse resolution global climate models and by fine resolution regional climate models, with larger increases for more-extreme events. Hence, increases in damage related to heavy rainfall are anticipated due to climate change. Further reading Fowler, A.M. and Hennessy, K.J. 1995. Changes in daily precipitation under enhanced greenhouse conditions. Climate Change 1995.