Other rewards to help with environment

According to http://www.utilitarian-essays.com/dollar-worth.pdf, 1$ donated to VO prevent's between 100 days and 51 years
of factory farming.

Based on back-of-the-envelope calculations (that assumes all of the reduced time is all chickens, which the most "green" animal), .5 to 80lbs of CO2 can be reduced for the same cost of reducing 1lb of CO2 through the existing carbonfund.org reward (2 cents).

Then there is the fact that factory farming is the biggest water polluter and the biggest contributor to land degradation.

It seems it would make more sense to make a reward to donate to an organization like Vegan Outreach than Carbon Fund if you want to reduce GHGs.