There are tons of answers you could have.
One, for example:
Increased levels of CO2 decreases DO levels in the water and suffocates organisms, leading to population drops that can cause a genetic bottle neck effect, thus decreasing overall biodiversity. This could lead to extinction
I believe that it would be a solar system. I hope this helps!:)
Answer;
-Medulla
Your life would be most immediately threatened if you suffered destruction of the Medulla.
Explanation;
The medulla oblongata is a portion of the hindbrain that controls autonomic functions such as breathing, digestion, heart and blood vessel function, swallowing, and sneezing. It is located in the brainstem, anterior and partially inferior to the cerebellum.
-The medulla is easily the most important part of the brain. It's functions are involuntary, or done without thought. We would not be able to live without the medulla because of the myriad of crucial tasks it performs including regulating blood pressure and breathing.