Research shows that anger triggers participation in social movements, while fear inhibits action. Therefore, fear is less likely to contribute to citizens’ engagement in protest. However, in the case of climate change, fear may play a distinct role and thus contribute to participation. Given the long-term consequences of climate change, we argue that it triggers different emotions across disparate age groups. We investigate the extent to which young, adult, and senior climate strikers experience fear and anger in relation to climate change. Furthermore, we analyze the contribution of these emotions to younger and older citizens’ motivation to demonstrate. Using a unique dataset collected among climate strike demonstrators in eleven cities around the world in September 2019, we examine the importance of anger and fear in explaining motivations to take part in the demonstration – to pressure politicians or to defend one’s interests. Overall, we find that protesters aged above 60 years old are less likely to fear climate change but are more likely to feel anger in relation to this issue than younger generations. On the other hand, those aged below 35 report the highest levels of fear in relation to climate change and are significantly less angry than senior citizens. In all age groups, both anger and fear are associated with motivation to defend one’s interest and to pressure politicians.