Jessica Alba joined other stars to help raise money for green charity. In honor of Earth Day (April 22), The Sak’s eco-extension, Sakroots, is hosting a celebrity bag auction. The auction is supporting The Nature Conservancy’s Plant a Billion Trees campaign.

For each dollar contributed to the initiative, one tree will be planted. Starting on the 8th and running to the 22nd, a celebrity autographed sakroots Pax Eco Weekender will be up for grabs, signed by Robin Wright Penn, Rosie Perez, Blair Underwood, Justine Bateman, Jessica Alba, Alec Baldwin, Sandra Oh and Mena Suvari.

I would love a bag signed by Jessica Alba! I took a look at the Sakroots website and they have some great looking bags on there.