Global warming is one of the top environmental concerns in the U.S, yet little is known about the effects of green advertising on different generational cohorts – Gen-Z, Gen-Y, Gen-X, and Baby Boomers. Specifically, environmental values (egoistic, altruistic, and biospheric) were assessed for differentially impacting ad attitudes and behavioral intentions across the four cohorts. Study-1 (n = 613) found the biospheric ad (plants and animals) to be more persuasive for Gen-Z and Gen-Y, with no preference shown for Gen-X and Baby Boomers, and no differences between the self (egoistic) and community (altruistic) focused ads. Based on these findings, Study 2 (n = 634) merged the four cohorts into two, Gen-ZY and Gen-XB, focused only on egoistic and biospheric, while introducing informativeness and task difficulty to better understand messaging preferences on attitudes and intentions to act. The findings revealed that Gen-ZY preferred to donate money for a biospheric ad with low information, while being motivated to volunteer their time when presented with a high information biospheric ad. Irrespective of ad appeal (egoistic or biospheric), Gen-XB had stronger intentions to donate for an advertisement with high information content (vs. low). Theoretical and advertiser implications are discussed along with future research avenues.