Thanks to Customize.org, one of the most prominent and well-established desktop customization sites on the web, and their Gaia project you can raise awareness for climate change with beautiful styles and themes for your computer desktop, iPhone, music player and instant-messaging program.
I am myself using the visual theme for XP and I must really say that this desktop theme is really beautiful, especially the Gaia icons. If you want you can also get the Gaia theme for the instant-message client Miranda and for the music player Foobar. And you can even enjoy the Gaia theme on your iPhone.
Just be sure to backup any data before installing the themes, especially before installing the Ux Theme Multi Patcher (which is needed to use the Gaia theme) on your computer. You can never be too careful!