The 'MEDIUM' Budget in CBAT is equal to the UKMO model-run and resulting 'Carbon-Budget' [2016 4% Low] in the UK Climate Act [UKCA]. Users can easily demonstrate this using the on/off 'toggle-switch' marked 'UKCA' on-screen top-right hand corner.
ON . . . . . . . OFF
When the switch is 'on', the emissions-budget in UKCA ["2016 4% Low"] is highlighted with a broken black outline around the Emissions-Budget [2016 4% Low]. The range of concentration levels in UKCA Upper, UKCA Medium & UKCA Lower], appears as well.
As can be seen here UKCA is equal to CBAT MEDIUM Budget.
These UKCA values remain in view until the toggle is switched off, whatever other user-choices and changes are made to the on-screen display.
This is to make comparison of all choices with the UKCA easier to follow.