Question

which of the following is not a main threat which plagues grasslands today?
urbanization
climate change
lasting effects from dust bowl
unsustainable agriculture

Explanation:

Urbanization, climate change, and unsustainable agriculture are ongoing threats to grasslands. The Dust - Bowl was a historical event in the 1930s in the United States, and its lasting effects are not a current main - threat compared to the others.

Answer:

Lasting effects from Dust Bowl