The proportion of storms that reach landfall and get to a category 4 or 5 in East/Southeast Asia has doubled and even tripled in some parts of the basin. Researchers have said that the increases in proportion and intensification may be the result of warmer ocean waters in coastal areas (which increase potential intensity). The increase in potential intensity leads to deeper convection and more rapid intensification. It is interesting because when they studied the various typhoons and their paths/intensity they found that storms that made landfall appeared to increase in intensity more (and more rapidly) than those that remained out at sea. The speed of intensifying was much greater than it was previously and is increasing even further with each year.
The increases in intensity are in line with the effects that previous findings about rising global temperatures predicted. The increases are expected to get worse by the end of the century due to the ocean taking up most of the excess heat that is trapped by greenhouse gases but a clear link between the increases and climate change specifically (not naturally varying climate patterns) is not yet certain.