Second loopback network interface (for netem)

I would like to add a second loopback network device on Linux, so that I have lo and (e.g.) lo2. This is so that I can use netem to simulate a throttled network over lo2 without compromising my standard loopback interface. Note that I can not use an alias interface here (such as lo:1) since netem will affect the underlying (lo) interface, not the interface alias. How can that be done?