Concerned about rising carbon dioxide emissions and their effect on the environment? Marshall Saunders, founder and president of the Citizens’ Climate Lobby (CCL), will join Des Moines Mayor Frank Cownie to present “Citizenship: The Solution to Global Warming” at 6:30 p.m. Tuesday, April 7, at the Franklin Avenue Library, 5000 Franklin Ave. in Des Moines. They will explain how ordinary people can organize to become a civil, nonpartisan and effective force for taking action to limit CO2 emissions. The presentation, sponsored by the Des Moines chapter of CCL, is open to the public. The organization’s goal is to create the political will for a livable world by empowering individuals to exercise their personal and political power, Saunders said in a release.