iCloud Drive taking up space on local drive? My computer seems to be keeping a local copy of my iCloud Drive folder. Is there any way to disable this? 

I know this because in my "Library" folder, there is another folder called "Mobile Documents" that links to the contents in my iCloud Drive folder. 

Also, when I click on "About This Mac", under "Storage", it includes the iCloud Drive folder's contents.

Is there a way for me to not keep a local copy of the iCloud Drive folder? I don't want it taking up space on my hard drive...
No, I don't believe this can be done. This is how the service works - copies of everything in the drive is copied to all devices that have the drive enabled.

You can choose to disable iCloud drive entirely, but you can't pick and choose what files arrive on which device.

Other cloud storage service like Dropbox and Google Drive behave in this way as well.