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The tornado that tore through Joplin, MO in May was one of the worst of last year's extreme weather events. But tornadoes have one of the more tenuous connections to climate change.

As we’ve noted before, last year was packed with extreme weather events, but it’s difficult to out-and-out blame any particular one of them on climate change. Explanations are often along the lines of, “This is the kind of thing that could become the norm in the future.” The science just isn’t quite there to able to pinpoint any single event and say exactly what caused it.

To try to sort out what we know from what we don’t, the University Corporation for Atmospheric Research (UCAR), a consortium of universities doing earth science research, has a new feature on its website, “In Depth: Weather on Steroids,” about that science: the science of attribution, as in, what can we attribute to climate change?

The site helps explain why attribution is so tricky, why it’s important, and how it’s improving.

It also has a handy video that compares the atmosphere to a baseball player, and climate change to steroids. If the player hits a home run, can you say that particular home run was due to the steroids?

The science is growing. As models get more specific, as computers get more powerful and can analyze more granular data, attributions–and predictions–will improve, too.