A personal problem is a problem that pertains to yourself and does not involve others. The term "personal problem" is often used dismissively to mean "it's not my problem".
UHHH............ debris that doesn't come from you?!?!
Fossil fuels are a problem due to their contribution to climate change through the release of greenhouse gases when burned. Transitioning to renewable energy sources is viewed as a solution to reduce dependence on fossil fuels and mitigate their environmental impact.
A limiting problem sets restrictions on what is possible or achievable, while a defining problem helps to clearly identify the key issue or aspect that needs to be addressed. Limiting problems can hinder progress, while defining problems provide a focus for problem-solving efforts.
A goiter is usually a dietary problem because it is commonly caused by iodine deficiency, which is necessary for thyroid hormone synthesis. An endocrine problem, on the other hand, would involve dysfunction of the thyroid gland itself, such as in conditions like hyperthyroidism or hypothyroidism.
Jeff