Climate change solutions aren’t free. But we know the approximate price and we have the money, according to Marilyn Waite of the Hewlett Foundation. A program officer specializing in climate and clean-energy finance, Waite, a 2006 Princeton graduate, says we need $1 trillion annually to reduce carbon emissions by 2050. The money is there and we know how to spend it — but risk aversion and a finance-as-usual mentality stand in the way.