The site looks great. Congrats on getting it up and running.
Does this feedback go straight to you? Or is it posted publicly? Unclear...
Here's a few thoughts from just perusing the sight briefly.
-Registration process was a little tricky with the date. It was hard to get the right year. Might want to add a simple text entry or something. Also, you might want to add a few more gender options. I dunno. I'm not the best person to ask about that.
-I liked that your tree is named Marcus. After Aurelius? I'm 90% done with Meditations right now.
-Is there some resources about how to harvest seeds and plant them? I read the article about how to buy seeds from Arbor Day, but I noticed I have a lot of those in my area. Can I just take some of their seeds?
-On the section "If planting trees won't be enough, what else can we do?" Can you provide more info? Which of these is the most effective? What are some alternatives I can do instead of just "using my computer less?"
-For the book, could your provide a sample? Maybe a few pics, some of the lines, etc.
-I like the projects section. That is cool.
-Also liked the Climate News section. Maybe you could include some links to further reading, other resources, etc.
Just my $0.02. You can ignore all this if you want. Good luck.