Unresponsive screen on Moto G after Lollipop update
It's actually a bug.

You have to do hard reset after the update:


Hold power button for 15 seconds and the device will be forced to shut down
Hold power button and volume down button simultaneously to enter fastboot mode and you will have factory reset option
Use volume down to navigate and volume up to select desired option
Once you have done a factory reset, click power button and the device will reboot.


If you still have touch issues you have to rollback to KitKat by flashing stock firmware.