$100 offset and/or $500 reimbursement for a hybrid

CHALLENGE 1:
"By reading through these bulletins, you will have learned about the reality of global warming, the excessive (and often wasteful) emissions that come from Americans, the many things we can do to reduce our emissions, and that we can purchase carbon offsets to nationally bring us closer to a position of zero carbon emissions. Accordingly, for each reader (up to 1000) who finishes the series, I will make a $100 contribution to one of three carbon offset organizations. You can specify the organization for the contribution. We will forward to them your name, address and e-mail along with the $100 contribution. They will later send you an acknowledgment of the carbon offsets in your name. "

CHALLENGE 2:
$500 reimbursement for a hybrid: Read all six chapters, give responses to the questions and they'll reimburse you $500 for your purchase of a Toyota Prius hybrid.