Next generation climate models are built with Julia. You would not pick a slow language for such a high performance dependent task.
You're confusing dynamic typing and type inference.
> Julia is dynamically typed, feels like a scripting language, and has good support for interactive use.
Literally on the front page.
As an implementation detail, it has a statically typed intermediate representation that's used for very aggressive and impressive optimization.
But that's an implementation detail, and is not what most people mean when they talk about a language being dynamically or statically typed.