When I read the OP quote, I see a logic that it doesn’t look like people have engaged with. She has already agreed on stewardship of the planet, so that’s not the issue, though that is the subject of a number of posts. Focusing on convincing people there is a problem is not the problem.
She says, “…if everyone did all that is humanly possible, it wouldn’t make a significant difference.” Therefore she is putting her trust in God. That’s her logic.
The question for her seems to be, what can I do that would make a meaningful difference? And since she can’t see anything, she’ll put her trust in God’s providence.
So can someone suggest to her/us/me something she/we/I can do that will reduce climate change?
Another unstated premise of the quote may be that God is more trustworthy than the “solutions” being offered by “politicians and their scientists.” Unfortunately scientists have betrayed the trust of many. The actual science in various areas may be sound, but there’s too much money in science looking for an a-priori conclusion, too much cherry picking of data, too much exaggeration of significance, too much scientism, and not enough integrity. Folks on this board probably excepted from this, but I trust you see what I mean.