I tell mine that things will get worse before they get better. But we saw with the covid vaccine what can happen when countries and scientists work together. We will start to see more of those kinds of collaborations as it becomes more evident to the richest countries that there really is a problem that is escalating quickly. The current ramp up in forest fires, hurricanes, floods, droughts, etc will provide the impetus for policy makers to start implementing significant changes.
I'm sorry the comments in here mostly suck. It's hard as a parent dealing with climate anxiety in a teen. Don't deny what your teen is observing but give them some hope.
Edit: https://www.washingtonpost.com/opinions/2023/09/06/climate-change-charts-data-optimism/
Before using cast iron daily, when I donated blood my iron levels were regularly at the lowest allowable limit or sometimes too low to donate. Once I started cooking with cast iron, I started getting comments about how great my iron levels are every time I donate.