Prior theories of individual behavior in recognizing public problems have centered on the role of policy entrepreneurs; institutional effects; information; and cultural, political, and social pressures. Our extension of these theories suggests that policy problem recognition is an attitudinal evaluation process. If the information is considered valid and the new attitude is negative in valence, then a policy problem is recognized. To test this theory, we use an embedded experiment in a national survey to measure the effect of persuasive messages on the concern for global warming. We find that the negativity of the message and the credibility of the source of the message both affect the level of increase in concern for global warming. Further, the impact of the message from the source is conditional based upon the recipient's ideology. This suggests that policy problem recognition is attitudinal and thus incorporates both analytical and affective components.