Imagine you have a diesel-powered car, and you can buy either diesel or biodiesel fuel (which is possible in some parts of the US). The cost of biodiesel is $34/GJ, and the biodiesel causes 18 kg CO2 emissions per GJ over its lifetime. The diesel costs $26/GJ and causes 72 kg CO2 emissions per GJ over its lifetime (4 times more!!). What is the cost of mitigation of choosing biodiesel?