Absolutely not. Full disk encryption is the only means to protect all of the data on your hard drive.
Otherwise, all that is required is to boot to a Ubuntu LiveCD and copy the data to a USD drive. Alternatively, the drive can be removed and placed in another computer or external enclosure and copied that way.
You can also create encrypted containers to files without encrypting the entire drive. But, I still recommend FDE. (https://support.apple.com/en-us/HT201599)