There has been no increase in extreme weather, just a increase in extreme weather reporting, plus because of increased populations, residences, infrastructure etc, increased damage and costs than which would have occurred in earlier times.

Sandy was not special there have been many similar and worse storms in the past, hurricane Gloria, New England hurricane of 1938,

The Great September Gale of 1815 (the term hurricane was not yet common in the American vernacular), which hit New York City directly as a Category 3 hurricane, caused extensive damage and created an inlet that separated the Long Island resort towns of the Rockaways and Long Beach into two separate barrier islands.

The 1821 Norfolk and Long Island Hurricane, a Category 4 storm which made four separate landfalls in Virginia, New Jersey, New York, and southern New England. The storm created the highest recorded storm surge in Manhattan of nearly 13 feet and severely impacted the farming regions of Long Island and southern New England.

The 1869 Saxby Gale affected areas in Northern New England, decimating the Maine coastline and the Canadian Outer Banks. It was the last major hurricane to affect New England until the 1938 storm.

The 1893 New York hurricane, a Category 2 storm, directly hit the city itself, causing a great storm surge that pummeled the coastline, completely removing the Long Island resort town of Hog Island.

Whenever there is an extreme weather event, such as a flood or drought, people ask whether that event was caused by global warming. Unfortunately, there is no straightforward answer to this question. Weather is highly variable and extreme weather events have always happened. Detecting trends takes time, particularly when observational records are rare or even missing in certain regions. An increase in extreme weather is expected with global warming because rising temperatures affect weather parameters in several ways. Changes in the frequency of extreme events coinciding with global warming have already been observed, and there is increasing evidence that some of these changes are caused by the impacts of human activities on the climate.

How global warming affects weather parameters

Rising temperatures can have several effects on the factors involved in weather. For example:

They increase the rate of evapotranspiration, which is the total evaporation of water from soil, plants and water bodies. This can have a direct effect on the fequency and intensity of droughts.

A warmer atmosphere can hold more water vapour. The atmosphere now holds 4% more water vapour than it did 40 years ago as a result of increasing temperatures. This increases the risk of extreme rainfall events.

Changes in sea-surface temperatures (SSTs) also have an effect by bringing about associated changes in atmospheric circulation and precipitation. This has been implicated in some droughts, particularly in the tropics.

These changes don't automatically generate extreme weather events but they change the odds that such events will take place. It is equivalent to the loading of dice, leading to one side being heavier, so that a certain outcome becomes more likely. In the context of global warming, this means that rising temperatures increase the odds of extreme events occurring.

Lol at the alarmists. They pretend there was never any extreme weather before 1970, try to link any unusual weather event to CAGW and now say "Uhhhhhhhhhhhhhhhh... what do you mean there's been an uhhhhhhhhhhhhhhhhhhhh... increase in severe weather over the past 10 years. Uhhhhhhh... who told you that? Uhhhhhhhhh... it wasn't us. Uhhhhhhhhhh!!!!!"

Maybe it's getting hard to keep the lies straight.

Alarmist: "CAGW is real and it will send temperatures skyrocketing."

Skeptic: "There's been no warming for about 14 years."

Alarmist: "No one said temperatures were going to skyrocket. Besides what's really bad is that CAGW has caused increases in EXTREME weather."

Skeptic: "Well if there's been no warming for 14 years why has there been an increase in extreme weather?"

Alarmist: "No one said there has been an increase in extreme weather. OMG, you are such a denier."

It all depends on who is doing the talking. To many, Hurricane Sandy was devastating and there was much hype and hoopla saying this was the worst. And it was bad, considering all the damage. But the hurricane, statistically was a tropical storm at the time it hit landfall. Al Gore went on record, blaming Hurricane sandy on AGW. Yet you see the temperatures for over a decade have lessened. All the while CO2 has increased.

Quote by Sir John Houghton, pompous lead editor of first three IPCC reports: “If we want a good environmental policy in the future we’ll have to have a disaster.” And it matters not, to some, whether that disaster is real or not.

So you see, these leaders don't care whether we are in a crises or not, they have an agenda and they will present it.

Quote by Paul Watson, a founder of Greenpeace: "It doesn't matter what is true, it only matters what people believe is true."

So you make a good point. If the temperature goes down, then the extreme weather conditions should go down, if you follow the greenie line of logic. But the weather patterns are much the same as they were seventy two years ago, when I was born.

Quote by Will Happer, Princeton University physicist, former Director of Energy Research at the Department of Energy: “I had the privilege of being fired by Al Gore, since I refused to go along with his alarmism....I have spent a long research career studying physics that is closely related to the greenhouse effect....Fears about man-made global warming are unwarranted and are not based on good science. The earth's climate is changing now, as it always has. There is no evidence that the changes differ in any qualitative way from those of the past.”

What part of "loading the dice" can you not understand 24-7 365 days a year?

It’s hard to say with any degree of accuracy whether there has been an overall increase in extreme weather events wholly within the period of the last ten years. To do that you’d have to compare say the period from 2008 to 2012 with the period from 2003 to 2007, this is far too short a time period to draw any conclusions.

Over such short periods of time it is possible to find one type of weather event that has increased in frequency and/or intensity, whilst at the same others will have decreased.

For example, from 2003 to 2007 there were five serious heatwaves and seven category five hurricanes, in the five following years there were 16 serious heatwaves and no category five hurricanes. If we tried to draw a conclusion from that we could be tempted to say that heatwave numbers are more than tripling every five years and cat 5 hurricanes are now a thing of the past.

So really, your question can’t be answered.

It’s better to look at how the weather has changed over periods of 60 or more years, that way we can compare one period of at least 30 years with a preceding period of the same duration. Now this is something the skeptics really wouldn’t want to see.

I don’t think they like the fact that there were four heatwaves between 1953 and 1982 compared to 28 between 1983 and 2012 or that the number of flood events worldwide increased five-fold from the 1950’s to the present day.

What seems likely, for the foreseeable future at least, is that the number of extreme weather events will level off and stay around the mean values over the last 10 to 15 years. It’s still substantially higher than it used to be, but at least it’s not continuing to worsen.

It seems that a sensible answer is in order. Oh! Never mind. It seems that the alarm bells aren't ringing when a sensible question is asked. In reading many of the answers it's easy to conclude that extreme weather events have always been part of natural climate variability and no conclusions can be drawn in such a short time period. If we could somehow document the entire history of the climate on a day to day basis, then maybe some conclusions can be drawn, but we are talking about 4.5 billion years of climate activity. 10 / 4,500.000,000 = ?%.

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pegminer - Sandy had one unique quality that increased its intensity. It met up with a cold front from the northwest. That was clearly shown by the meteorologists. They were drawn together to form a more perfect climactic (or climatic) condition.

I'd have to agree that 10 years is far too short a time period. I'm curious though, where is your data showing that extreme weather has increased over the past 10 years?

There isn't the liberal media wants you to think it is . A storm hit NYC they act like

it never rained there before . Run

Bogus and biased newscasting .

Ten years is a very short period climatologically speaking, and it's even shorter when you're trying to study the climatology of extreme events, which, by definition, are rare events. First, looking at temperatures over that short a time period is silly, considering the year-to-year variability that is NOT connected with global warming. I don't think there's anything wrong with the quotes that you give, the problem is with you thinking that we're going to be able to interpret them with regard to the global mean temperature over the last ten years.

I don't see you presenting any evidence that extreme events have increased over the past 10 years. Which ones do you think have? I consider tornado numbers unreliable because we have no way of objectively counting tornadoes. Tropical cyclone numbers are small, so the errors associated with their numbers are going to be relatively large. I think the same would apply for things like blizzards and heat waves.

EDIT: BB, your sympathy for the scores of people people who died in Superstorm Sandy, and the millions of others that suffered damage in the second most costly storm to ever hit the US is duly noted. Sandy was an extremely large and destructive storm, that you and other deniers can't appreciate that is further indication that your knowledge of weather and climate is deficient.

EDIT for your additional details: While it would be very interesting to have the data on water vapor that you ask about, we simply don't have that. The most accurate ways of measuring atmospheric water vapor are relatively new, such as GPS and microwave radiometers. There are very few climatological records derived from these instruments that go back more than ten years. While people attempt to do it, I don't have much confidence in radiosonde observations of atmospheric water vapor for climatological purposes. The hygristors have had many problems with them and have been through a lot of changes, so you have to do instrument intercomparisons. You also have to realize that we only expect the equilibrium (saturation) vapor pressure to change about 6% for each change in degree celsius. Since the air is typically not saturated, the actual vapor pressure would change less than that, and of course you are choosing a ten year period that has a temperature change much less than even one degree, you won't expect big changes.

EDIT for BB: Don't try and blame me for the crass and stupid things that you say, if what you wrote doesn't accurately express your feelings, then change your answer.

EDIT for Sagebrush: Sandy was NOT a tropical storm at landfall, to quote the NHC:

"The center of Post-tropical Cyclone Sandy then made landfall at about 2330 UTC near Brigantine, New Jersey, just to the northeast of Atlantic City, with an estimated intensity of 70 kt and a minimum pressure of 945 mb."

Sandy no longer had tropical characteristics, so its designation was changed to "Post-tropical Cyclone," but as you see from the intensity, it STILL had hurricane force winds (65kt or > for hurricane). The minimum pressure was also the lowest ever recorded in the US north of North Carolina.

EDIT for Pat: It was an extremely large storm before it made the extratropical transition--which is not particularly unusual, by the way. You have to expect that in mid-latitudes.

While we are not told that there is no confirmed direct link between extreme weather and warming (or more specifically one particular event cannot be attributed), we are told there is a relationship nonetheless. For example:

"climate change can add to the destruction of extreme weather"

"increasing atmospheric temperatures is like 'loading the dice'"

"frequency of some events may not change but intensity may increase"

"one in a hundred events can occur one in ten or one in five times due to warming"

Let's look at the SST and global surface temperatures for the past 10 years: http://www.woodfortrees.org/plot/hadcrut4gl/from:2003/plot/hadcrut4gl/from:2003/trend/plot/hadsst3gl/from:2003/plot/hadsst3gl/from:2003/trend

The trend is clearly down for that time frame. This question is not about the long term trend which cannot be determined from a short 10 year period. This question is not about whether global warming has stopped, or paused or accelerated. It is about the past 10 years.

Given the 10 year trend in temperatures, why have extreme weather events increased in the past 10 years? Or have they not?

There has been no increase in "extreme weather events".

Depending on where they hit determines how "extreme" they are......If they hit in a highly populated area, then they are deemed "extreme" by the media and anyone else wanting taxpayer handouts to pay for rebuilding an already dilapidated infrastructure due to local government's short-sighted lack of routine maintenance/replacement....Thunderstorm Sandy on the East coast comes to mind.

WTF is going on. Is today opposite day or are warmons starting to back off there cries about extreme weather and how if we don't do something now they are going to get worse for some reason?

http://www.woodfortrees.org/plot/hadcrut...

http://www.google.com/imgres?imgurl=http...

http://ngm.nationalgeographic.com/2012/0...