Thread by @KHayhoe

"Was it caused by climate change?" is the most common question when we hear about an extreme event. But when it comes to hurricanes, that's the wrong question. The right one is, "how much worse did climate change make it?" (thread)

Climate change isn't making hurricanes more frequent. But tropical storms - hurricanes, cyclones, typhoons - are fueled by the ocean, and 93% of the heat trapped inside the climate system by human emissions is going into, you guessed it, the ocean. So here's what's happening...

As the ocean warms, hurricanes are:
* intensifying faster
* getting stronger
* have a lot more rainfall associated with them
* getting bigger, too
* moving more slowly
* and then there's sea level rise, which makes storm surges worse

For a given hurricane, it is now possible to determine the extent to which climate change made it worse. For Harvey, it's estimated that climate change increased its precipitation 38% and its likelihood by 6x. Sources: agupubs.onlinelibrary.wiley.com/doi/abs/10.100… and pnas.org/content/114/48…

If you'd like a short, up-to-date primer on what the science says about hurricanes and extreme storms, start with section 8 here, including the box about Harvey: nca2018.globalchange.gov/chapter/2#sect… and then read Chapter 9 of the National Climate Assessment here: science2017.globalchange.gov/chapter/9/

And if you'd like to read more, here's an article that summarizes what we know about hurricanes and climate change #Dorian2019 nytimes.com/2017/08/25/us/…