How does global warming affect hurricanes?

Answer 1

Global warming is adding heat to the atmosphere and oceans. Heat is energy, so this energy is used to power bigger and stronger "weather events"!

The following are opinions on the affect of global warming on hurricanes:

Global Warming Causes More Hurricanes

It could be that the tropical oceans will become warmer with a simultaneous decrease in upper atmosphere temperature, which will cause stronger convection, which will help tropical storms to become more organized and stronger so there will be stronger hurricanes.

Global Warming Causes Less Hurricanes

It is not just warm water which causes hurricanes. It is the temperature difference between the ocean surface and the upper atmosphere. The higher that temperature difference, the more hurricanes will form, and the stronger they will be. Global warming models all agree that the temperatures will rise more in the upper atmosphere than at the surface. Since the upper atmosphere is cooler than the ocean surface, this means that the temperature difference will become smaller. Therefore, fewer hurricanes. And less intense hurricanes.

(Note, the above discussion is based on the theory of Anthropogenic Global Warming. If the warming were natural, it would not necessarily be true that the upper atmosphere warmed more than the surface. In fact if the warming were natural, most likely, the surface would warm more than the upper atmosphere. Therefore, if there were more hurricanes, or more intense hurricanes, that would be evidence that the warming we are experiencing is, in fact, natural.)

This representation of the surface/upper troposphere temperature differential as a distinction between natural and anthropogenic global warming is a false dichotomy, especially when some of the warming (i.e., height of the tropopause rising) is due to changes in stratospheric ozone cooling the lower stratosphere. But anyway, the current discussion on hurricanes and global warming is centered on whether increases in sea surface temperature will be more rapid than upper tropospheric warming. Of course, it is far more complicated than just delta T, and you need to incorporate changes in lapse rates throughout the atmosphere as well as how this translates into the height of cloud tops. Shen et al. (see related link for discussion) found that the increase in upper tropospheric temperature would need to be more than double the rise in ocean temperature to cancel its effects.

The official studies

New data analysis has shown a direct relation between Atlantic Ocean Warming and stronger hurricanes. Scientists funded by the National Science Foundation, the University of Wisconsin-Madison and NOAA's National Climatic Data Center in Asheville, North Carolina, reported the finding of strong links between global warming and extreme weather conditions as hurricanes.

The energy of a hurricane derives from rising hot air, which sucks in more air underneath it, which causes wind. Global warming causes more air to be more heated.

The theory is that these storms are created by warm air over cooler water. This effectively becomes a water pump pushing large volumes of water into the atmosphere. If the Oceans were cooling and the atmosphere itself were warming, then this difference would create a larger and faster water pump.

To date, there is no evidence of this situation happening. Storms have not increased in size or frequency since 1850. In fact the levels may be slightly down in terms of overall days of storms.

The idea that storms could increase should global warming start to occur is also questionable as the water pump action requires a large difference between air and water temps. If global warming is to occur, most climate experts claim we would start seeing this in our oceans first, as they tend to mirror the overall temp of the atmosphere.

If this is the case, storms could decrease in size and strength. There is some inconclusive evidence of this situation occurring.

Neither is easy to prove as the temps have not really changed since we were first able to start observing the entire planet in 1979. The entire satellite history is 40 years old and 25% of the data shows cooler trends since 1998.

Answer 2

Warm ocean waters are the energy source for hurricanes. As the seas warm with climate change hurricanes will become more frequent and stronger. In addition these supercharged hurricanes will affect the jet stream redirecting arctic air into new location creating more severe rain and snow problems in areas not directly affected by the hurricane itself.