Climate change is a global crisis posing exceptional threats and demands on our younger generations. Our aim was to understand how climate-change worry and hope relate to climate-friendly behaviors, life satisfaction, and negative affect in young people across Qatar and Sweden—countries with different climates and challenges. Data from young people between 16 and 19 years of age from Sweden (n = 277; 61.37% female) and Qatar (n = 134; 49.25% female) were used. Participants completed questionnaires online. Correlational and regression analyses were used to test bivariate and unique associations and moderation effects. Climate worry was positively associated with climate-friendly behaviors in both samples. Climate worry was positively associated with negative affect and negatively associated with life satisfaction in the sample from Qatar, whereas in the Swedish sample it was only positively associated with negative affect. There was a significant interaction between climate hope and worry on climate-friendly behavior (interaction coefficient = 1.44, p = 0.0032) in the sample from Qatar, and on life satisfaction (interaction coefficient = 0.61, p = 0.036) in the sample from Sweden. Climate hope’s positive effects on these outcomes were significant at higher levels of worry. This study shows the importance of considering both the unique effects and the interplay between hope and worry across regions to understand the impacts of the climate crisis on young people.