This is Hank Green, welcome to SciShow Breaking News.

Hurricane Sandy has been described as a once-in-a-lifetime storm, and after seeing the destruction it has dealt, I certainly hope it is.

Many of you have been asking to learn more about how it started, what it means, so here are some answers to a few of your frequently asked questions.

First big question, what was up with this storm?

So remember how our planet is covered in a nice happy layer of gas called the atmosphere?  Well it's hard to fault it too much for its occasional temper since, you know, we have to breathe and stuff.  But it does occasionally have its tantrums, and tropical cyclones are the biggest tantrum of all.

The air at the surface of the Earth, though you might not feel it, is constantly being crushed by the weight of all of the air on top of it.  This is what we call "air pressure."  Hot air rises, because it's less dense or has a lower pressure.

Basically, it's lighter than the air around it.  Now it's one thing when it's the air coming off the top of your hot cocoa; it's quite another when it's the entire Atlantic Ocean. 

Hurricanes and other tropical cyclones are basically just enormous amounts of hot, high-pressure, moist air from the surface of the ocean rushing to higher, cooler areas up in the atmosphere, and on the way up, dropping their moisture into clouds and transferring the heat energy into wind. 

Sandy started just this way and caused plenty of damage as a strong yet typical hurricane.  But how did she become a 1,000-mile-long superstorm?  Usually upon meeting colder surface temperatures, the difference between the higher-altitude air and the surface air temperatures become less significant and the storm loses power.

But Sandy, she ran into a truly strange confluence of events that helped her transfer into a different category of superstorm: the extratropical storm. 

The first of those weird events: it is really late in the year for a storm like this to keep its power for so long.  This is in part due to higher-than-usual sea temperatures in the Atlantic.

Second: A high-pressure system over Greenland, potentially caused by lower-than-usual sea ice levels, was pushing Sandy away from the ocean and, thus, toward land.

And finally, because it is so late in the year,  a cold weather/high pressure system from the north was able to move in and meet Sandy with two terrible results.   

First, the system sucked Sandy lengthwise across North America, more than 1,600 kilometers at its widest, from New York to Iowa.  

Second, the cold weather gave the storm a new way to power itself.  Instead of the relatively similar temperatures between the Earth's surface and the air in the storm, a new power source started up between the storm and the cold air from this new system making Sandy into the superstorm that it was.  

Question number two: Has this ever happened before?

Well extratropical cyclones aren't common, but when they do happen, it's typically in the autumn, since they require warm-weather hurricanes combining with winter-like cold fronts.  1991's Halloween Hurricane, immortalized in pop culture as the perfect storm, was an extratropical cyclone.  

So was the worst windstorm to hit Britain in the nineteenth century.  The Royal Charter Storm of October 1859, which sunk more than 300 ships off the coast of Wales.  In fact, it's thought that the very science of meteorology was inspired by another extratropical cyclone: the surprise storm that sank the British fleet in the Black Sea during the Crimean War in 1854. 

After that one, people started to think maybe there is a way to try and predict these things.  That would be helpful... for the war effort.

And our final question: This is global warming, right?

Of course there is a difference between weather and climate, but part of that difference is context. While storms like Sandy have happened before, this one has taken place among at least two climate record breakers that are worth considering.

First, there is the record melting of sea ice that I told you about last week. According to The New York Times, some scientists say that the systems off Greenland that kept Sandy from going out to sea are consistent with large amounts of open, unfrozen Arctic sea. 

Second, sea surface temperatures off the Northeasters US this year were the highest ever, which could have helped give Sandy the energy it needed to make its way to the north in the first place. While we're at it, I might as well point out that last month tied with September 2005 as the warmest September on record.  

Now we can hope that the changing climate will not cause more severe weather events like this, but as one of the world's largest reinsurance firms has just released a report saying that weather-related disasters have more than quintupled since 1980 in North America, it's hard to believe that we aren't in for more.

Thank you to all of the people who helped predict this storm, helped minimize its damage, and are helping people affected by it now.  I hope all of you out there are safe, and that everyone's power is back on soon.

If you have any questions or comments, we're on Facebook and Twitter and, of course, down in the comments below.