Here's my opinions. Please take them with a grain of salt.
- I don't like yellow. I would tone it down a little.
- The green is nice, but I would try one or two shades lighter.
- Fonts are easy to read and look fun.
- All of your links apear to be working well.
- Responsiveness is really good.
- I like the GreenPeace ad that comes up for me.
- One thing I noticed was that the paypal link at the bottom goes to a Spanish language page. Seems odd that we're doing English on the front page and then it changes. I now can't make a donation, since I can't read it.
- You might want to add a copyright date to the bottom of the first page.
Overall a very solid site.