From: https://en.wikipedia.org/wiki/List_of_Atlantic_hurricane_recordsIncreasing temperature is likely to lead to increasing precipitation[6][7] but the effects on storms are less clear. Extratropical storms partly depend on the temperature gradient, which is predicted to weaken in the northern hemisphere as the polar region warms more than the rest of the hemisphere.
David Strumfels -- However, from https://en.wikipedia.org/wiki/Physical_impacts_of_climate_change:
Storm strength leading to extreme weather is increasing, such as the power dissipation index of hurricane intensity.[17] Kerry Emanuel writes that hurricane power dissipation is highly correlated with temperature, reflecting global warming.[18] However, a further study by Emanuel using current model output concluded that the increase in power dissipation in recent decades cannot be completely attributed to global warming.[19] Hurricane modeling has produced similar results, finding that hurricanes, simulated under warmer, high-CO2 conditions, are more intense, however, hurricane frequency will be reduced.[20] Worldwide, the proportion of hurricanes reaching categories 4 or 5 – with wind speeds above 56 metres per second – has risen from 20% in the 1970s to 35% in the 1990s.[21] Precipitation hitting the US from hurricanes has increased by 7% over the 20th century.[22][23][24] The extent to which this is due to global warming as opposed to the Atlantic Multidecadal Oscillation is unclear. Some studies have found that the increase in sea surface temperature may be offset by an increase in wind shear, leading to little or no change in hurricane activity.[25] Hoyos et al. (2006) have linked the increasing trend in number of category 4 and 5 hurricanes for the period 1970–2004 directly to the trend in sea surface temperatures.
From http://www.principia-scientific.org/evaluation-of-climate-change-reconsidered-ii-physical-science.html:
As to extreme weather events that some claim are occurring with greater intensity and frequency because of the increase in atmospheric CO2, the data do not support that claim. There has been no recent increase in the intensity or frequency of hurricanes or typhoons either globally or in any specific ocean area. Nor has there been any significant increase in stormy weather or precipitation frequency or magnitude.
From https://www.google.com/search?q=hurricane+frequency&safe=off&hl=en&qscrl=1&rlz=1T4GGLS_enUS532US532&tbm=isch&tbo=u&source=univ&sa=X&ei=RXG8Uoy7OMuvsQSV5IDgAw&sqi=2&ved=0CCwQsAQ&biw=1219&bih=768#facrc=_&imgdii=_&imgrc=Pn-UM9t-lJ3krM%3A%3BBtsIDrdHWR7hjM%3Bhttp%253A%252F%252Fimages.sciencedaily.com%252F2009%252F09%252F090922112207-large.jpg%3Bhttp%253A%252F%252Fwww.sciencedaily.com%252Freleases%252F2009%252F09%252F090922112207.htm%3B600%3B489
Sorry if some of these images are hard to read. Yet they do seem to challenge the IPCC and media's assumption that higher CO2/temperature must lead to more and more intense hurricanes.
