Final answer:
Based on the provided information, a strong case can be made that the people of this new land might mostly fear impending environmental catastrophes (B).
Step-by-step explanation:
This is evident from various observations about cultural attitudes towards ecological disasters, the sustainability of human civilization, and the impact of global warming. For instance, there's a pessimistic view regarding the likelihood of a cultural enlightenment taking place soon enough to prevent ecological disaster, suggesting a widespread recognition of environmental threats.
Moreover, discussions about human activity transforming the planet's environment indicate concern over ecological balance and the necessity to adapt to or mitigate the effects of climate change.
Finally, the cornucopian theory is mentioned (a), which posits that human ingenuity will provide solutions to overpopulation challenges, yet the context suggests that chances of successful implementation of a global plan for sustainable living are uncertain, reinforcing the anticipation of environmental challenges over technological utopias or global prosperity.