The go-to data point used to indicate whether an institution is helping students reach success has tended to be its graduation rate. Post-graduation employment is another indicator but the definition of student success has evolved to include many more areas.
However, many examples exist of non-linear and sometimes abrupt changes in ecosystems. A change may be gradual until a particular pressure on the ecosystem reaches a threshold, at which point rapid shifts to a new state occur. Some non-linear changes can be very large and have substantial impacts on human well-being.
However, human activities often affect ecosystems in negative ways because human systems are not closed loop systems [closed-loop system: A system in which feedback from the output is 'fed back' into the system to modify the way it works.] . Human waste enters other natural ecosystems, where it can cause them to become unbalanced. 1  Sometimes this waste can build up to harmful levels. Examples of human waste that can affect ecosystems are: 2  household waste. 3  industrial waste. 4  agricultural waste. 5  gases produced when fossil fuels are burned.