There is no one answer to this question as the cost of saving the planet will vary depending on what actions are necessary and how much support is available. Some estimates suggest that it would cost upwards of $100 trillion to save the planet from impending doom, while others believe that a more conservative approach would find it costing around $50 trillion. Whichever path is chosen, everyone agrees that it will be a costly endeavor - though not infinite in terms of costs.