How can I islamically defend my decision to not have kids to my parents?

Asalamwalaikum everyone! This is my first post, so please forgive me for any formatting errors/if this isn't the right sub for this kind of question.

I'm a 22F Pakistani American, and I've come to the age where my parents want to arrange a marriage for me. I have decided to turn down a suitor because he wants children, and I have never been interested in having children. When my parents asked why, I provided the following reasons:

1. I don't want to pass on health issues (heart problems, diabetes, cancer) that run in my family
2. I don't want to bring children into the world due to political/environmental issues
3. I have 0 interest in most forms of physical intimacy, and (I assume) that will extend to those involving the creation of children

Unfortunately, my parents don't see not wanting kids as "real" and think I'm simply coming from a place of fear. They don't see this as a valid reason to turn down a possible suitor. Let me be clear: maybe my perspective on having kids will change in the future, and that's perfectly ok, but where I am NOW, I don't see myself ever having children. I don't think it is fair to marry someone who wants kids simply on the off chance that my perspective MIGHT change someday.

I would appreciate any advice, particularly that which approaches this from an Islamic perspective, that I could use to better help my parents understand my side.

Jazakallah khair!