Unfortunately I couldn't get my son into private kindergarten. He brought me a little book he made about climate change, and he said he was scared that the world is going to end. He is 6.
I sat down with him and told him a bedtime story. I told him that when I was a little girl, my teachers told me that when I grew up, the air outside would be poisonous, the rain would be acid and burn your skin, and that there would be so much trash that the world would be covered in mountains of garbage. They told me that the whales would all be gone, that the world would get too hot and the ice caps would melt and cover all the land in water. I told my son that when I went home from school, I told my daddy, his grandfather, what they said. My daddy, his grandpa, told me that when he was a little boy back a long long time ago, his teachers told him that the world was going to freeze, and all the plants would die and many people would starve. But the world didn't freeze, nor did it heat up so the ice caps melted. There are still whales in the ocean, the rain is just rain, the world isn't covered in trash and the air is cleaner than it was 100 years ago, and there are more trees in our state than back then, too. They have made these predictions for generations and none of them ever come true. I told him not to be afraid, when he's an old man the sun will still shine, the rain will still fall, the grass will still grow and the birds will still sing. He was very relieved and I could see his tension melt away. Talk to your kids. It's the only way to deprogram them before it sticks permanently.
I often do this why my son who, like you, I couldn't get into a private school. We often talk about what he's learning and I get to see all his homework since he's had split days this year due to the plandemic. So far, I've only had to prepare him for the fact that many of his teachers and peers do not believe in God like he does and he shouldn't be embarrassed about thinking differently but treat them with kindness--even if they mock him. I'm waiting for the diversity, social justice lectures to begin.
I also grew up in a public school and every time they started spouting off crap, I would take it to my dad who'd kindly set me straight. Likely why I didn't have some huge rebellious change in attitude and beliefs when I went to college like a majority of the people I knew. I've grown up thinking "different than the world" my whole life and I just expect it. I took for a grain of salt what a teacher's opinion was whenever things started to "stink" (e.g. history sounding a little too biased towards certain individuals. science painted a little too much with a doomsday brush, too much criticism for well-loved classics.) You know: thinking for myself.