The social issues are poverty and an aging population.
The social issues that Japan faces are poverty and an aging population.
Poverty and an aging population are social issues.
「貧困」→poverty
「高齢化」→aging population (もしくはpopulation aging)
*ちなみに、「aging」は「ageing」と書かれる場合があります。
「社会的問題」→social issues
(In Japan,) The social issues are poverty and an aging population.
→(日本では)貧困と高齢化が社会的問題です。
The social issues that Japan faces are poverty and an aging population.
→日本が直面する社会的問題は貧困と高齢化です。
Poverty and an aging population are social issues.
→貧困と高齢化は社会問題です。