According to some modern environmentalists how should mankind be viewed

I believe the answer is: They propose holting the growth of human population and beginning a gradual decline of human population to a sustainable level.

In order to do this, they propose birth control. This can be done by both educating the people regarding the high expense of having too many children and teaching the youngster to use protective measures (such as condoms or pills) to prevent early pregnancy.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

answer; reactive is your answer; good luck