How is global warming affecting the climate?

Global warming, at its most simplistic, simply results in hotter weather. The difference over the entire twentieth century is only 0.75 degrees Celsius, an apparently small increment, but what is really happening tends to be a slightly higher number of very hot days in some areas. Moreover, local effects can mean that certain areas suffer from periods of unprecedented heatwave. For example, Moscow, renowned for its cold weather, recently experienced a long period with temperatures over 40 degrees C (104 degrees Farenheit).

Changing patterns to wind and ocean currents can result in the freezing winters recently experienced in the United States or, at worst, moving the Gulf Stream away from the United Kingdom a dire effect which, if it occurs, would lower the temperature of the British Isles dramatically, with devastating conquences. So global warming can mean local cooling, at least on an occasional or random basis.

We have already begun to experience more frequent severe hurricanes, and can probably add tornadoes to that.

• Of the 8 years with the most hurricanes since 1851, 3 have been in the last 20 years and only one prior to 1916.
• Of the 8 years with the most major hurricanes since 1851, 3 have been in the last 20 years and none prior to 1926.
• The year 2005 was the year with the highest Accumulated Cyclone Energy.

Some areas will experience more frequent severe flooding, while other areas will experience severe and prolonged droughts. The Arctic sea ice is expected soon to melt entirely during summer months. Rising sea levels and more powerful storm surges will devastate some communities along the coasts and in low-lying areas.

 

A:

Actual data points to the fact that Level 5 Hurricanes have decreased in numbers over the past several decades.

As a matter of fact, recent data of total storm intensity (ACE) is showing an overall downward trend to the lowest levels overall since 1977. ACE is the convolution or combination of a storm's intensity and longevity. Put simply, a long-lived very powerful Category 3 hurricane may have more than 100 times the ACE of a weaker tropical storm that lasts for less than a day. Over a season or calendar year, all individual storm ACE is added up to produce the overall seasonal or yearly ACE. Detailed tables of previous monthly and yearly ACE. These were found on the Florida State Website.

The issue we have with pre 1979 data is summed up by A journal of Science writer, Landsea:

"Extreme hurricanes like Katrina were likely as common around the world 30 years ago as they are today, Landsea says. But since satellite imagery was poorer, storm intensities were underreported."

 

A:

Global warming changes the climate because of the way the earth is warming, therefore creating water temperatures to also rise, and changing weather, with really bad storms.