learn Esperanto. The problem is that it takes up much more space than English
That's not how Esperanto works - it is not a philosophical language. While in theory it is 100% agglutinative, it is not used in that way, and the wordbuilding affixes serve more like a mnemotechnical device when learning the language (and it is very cleverly designed and very helpful).
As for the size, Esperanto is not longer or shorter than any particular other language - it is English that is somewhat shorter than the others, due to many mono- and disyllabic words. Also consider the fact that translations are usually longer than originals.
I just read this in the Wikipedia article on the Mattaponi River and it really tickled me. If only all language were so rational!