This Doctoral thesis studies how nudges can help protect the environment. Three empirical and one theoretical studies investigate applications of green nudges and identify situations where they should, or should not, be used to promote environmental conservation. In Chapter 1, we explore the interplay between nudges and financial policy instruments using an incentivized online experiment that reproduces daily energy behaviors. We find that these two tools do not perform better when implemented together than individually. Our results suggest that in some situations, displacements between behavioral and financial policy tools are more likely to arise than synergies. Chapter 2 presents a field study in which a behavioral intervention is used to promote energy conservation in the workplace. Using a difference-in-difference approach, we find a significant reduction in branches’ monthly consumption outside the work schedule only, but not on overall consumption. Our findings suggest that nudges that are effective in the household context do not necessarily prompt behavioral change in the working environment. In Chapter 3, we develop a behavioral model for the usage of in-home displays that provide real-time feedback on energy consumption, focusing on social housing. On top of the cost-benefit analysis between financial and moral utility, on the one hand, and the effort from using them, on the other hand, we add the role of cognitive biases. This study seeks to improve the design of behavioral policies aimed at tackling energy poverty. Chapter 4 presents an incentivized online experiment that studies moral cleansing in the interpersonal and environmental domains. We find that bad behaviors that impact others trigger costly moral cleansing, whereas those that impact the environment do not even trigger costless cleansing. This empirically shows that people perceive environmental issues differently from other moral issues.