Question 12 (Mandatory) (1 point) development' became most commonly used after which event? After the first UN conference on the environment in 1972 After the release of the 'Our Common Future' report in 1987 After the 2008 collapse of the global economy, since it was connected to unsustainable growth After the 1997 greenhouse gas emission reduction treaty (the Kyoto Protocol) was put together The concept of 'sustainable