This is scientific Americans 60 second science. I'm Adam Levy.

On September 20th, 2017, a huge storm, Hurricane Maria, made landfall on Puerto Rico.

While the initial estimates suggested around 60 people lost their lives as a result of this horrific

hurricane, the official figure was later raised to the thousands.

We've all seen it on the news, right?

We all watched how, you know, or heard about how people didn't have power for, you know, a month

after, three months, six months, a year after,

apparently there's still some people in the island that still don't have power.

David Keelings, a geographer at the University of Alabama.

With the cost to America of $90 billion, Hurricane

Maria was the third most financially destructive in US history. But just how unusual was its intensity?

Keeling set out to compare Maria to all the other storms that have hit Puerto Rico

since records began in 1956.

Maria is more intense than any one of those other 128 storms that we have in the record.

It's dropped more rainfall than any one of those other storms and to a significant amount about 30 to 60 percent

more rainfall than any other storm in history in Puerto Rico.

So the question is, could climate change have played a role in this devastating

record rainfall? While it's not possible to say a single storm is caused by

climate change, it is possible to investigate whether climate change made a storm more likely.

And this is exactly what Keelings investigated. He calculated how likely Maria was to take place in today's climate and in a world where we hadn't altered the global climate as much.

So we dial back global temperatures to the 50s, we dial back CO2 to the 50s, we dial back cloud cover to the 1950s,

and then we calculate the probability of Maria again, and then we compare those two probability

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