New Scientist: Storm surges are one of the effects of powerful storms like hurricanes. Aslak Grinsted of the University of Copenhagen determined what storm surges look like in tide-gauge data by comparing the surge data with records of recent hurricanes. He then examined data collected since 1923 by tide gauges on the Atlantic coast of the US and in the Gulf of Mexico. That allowed him to identify all the major storms, even the ones not listed in meteorological records. Based on the trend he identified, the average number of yearly storms in 2100 will be 9.5, compared with just 5.4 in 1923. He also determined that there was a correlation between the number of large storms, such as Hurricane Katrina in 2005, and the average warmth of a year. Grinsted’s findings support theories that tie global warming to an increase in the number and strength of severe storms.