How do I get access to environment variables in my post block?

[red 888]

At the top of my pipeline (not inside a specific stage) I define an env:

environment {
    MYVARRRR = 'sdkfjlsjflsjflsd'
}

Now I want to use it in a function call in my post block. I had to do this to get it to work:

post {
    success {
        script {
            def MYVARRRR = MYVARRRR
            myFunction {
                someParam = "This is my var: ${MYVARRRR}
            }
...

This works fine, but is there a more elegant shorthand for this? Maybe an annotation that will grab the var from the calling parent or something? Why do I have to redefine the variable?