Question

the steps needed to reduce overpopulation that will have the greatest impact are
educating the public about the problems and reducing poverty.
leaving the problems for the next generation to address.
waiting for the affected species to leave an ecosystem.
make treaties with other nations.

Explanation:

Educating the public raises awareness about the issues related to over - population and reducing poverty can lead to lower birth rates as people have better access to resources and family planning. Leaving problems for the next generation is not a proactive solution. Waiting for species to leave an ecosystem is not a direct way to reduce over - population. Making treaties with other nations may not directly impact over - population reduction in a significant way compared to public education and poverty reduction.

Answer:

educating the public about the problems and reducing poverty.