mankind is
This answer is basically correct, but there is no single answer.
Overpopulation seems to be the best answer. Less people means more territory and Natural Resources for all. Most wars are fought over territory and natural resources. Pollution would not be a problem.
That only leaves Greed.
State governments
It was them or the USA and the USA was by far the greatest threat to Canada and other British colonies in North America.
The greatest man to ever grace this earth. He is possibly a god amongst mortals!
Samuel Adams
your mother
The main animal that is a threat to a panther would be man.
The greatest threat to man's existence caused by human changes to the environment would be deforestation. This is because it releases carbon dioxide into the air, decreases oxygen, and kills organisms.
The greatest threat to the spirit bear is Cole
It is us the Filipino who is the most greatest threat of Filipino Nationalism
The greatest threat to numbats would be the fox, an introduced species. It is closely followed by feral cats in the threat it poses to numbats.
The greatest threat to the stability of the slave families is that the family members were separated from the rest.
wind p[ower
Humans
turtles
The hyaena
The greatest band known to man-kind: Squeeze.
forest fires